blob: 6872b73e193d04a11e9d63b0d0dce1b81fdbf426 [file] [log] [blame]
Tim Petersb07352e2001-09-08 01:25:47 +00001What's New in Python 2.2a4?
2===========================
3
4Core
5
Tim Peters59c9a642001-09-13 05:38:56 +00006- The builtin file type can be subclassed now. In the usual pattern,
7 "file" is the name of the builtin type, and file() is a new builtin
8 constructor, with the same signature as the builtin open() function.
9 file() is now the preferred way to open a file.
10
Tim Peters1f47d112001-09-12 23:40:29 +000011- In 2.2a3, hash() applied to an instance of a subclass of str or unicode
12 always returned 0. This has been repaired.
13
14- In 2.2a3, an operation on an instance of a subclass of an immutable type
15 (int, long, float, complex, tuple, str, unicode), where the subtype
16 didn't override the operation (and so the operation was handled by the
17 builtin type), could return that instance instead a value of the base
18 type. For example, if s was of a str sublass type, s[:] returned s
19 as-is. Now it returns a str with the same value as s.
20
Tim Petersb07352e2001-09-08 01:25:47 +000021Library
22
Tim Peters16a77ad2001-09-08 04:00:12 +000023- operator.indexOf() (PySequence_Index() in the C API) now works with any
24 iterable object.
25
Guido van Rossumd8185ca2001-09-14 16:35:16 +000026- The smtplib module now supports various authentication and security
27 features of the SMTP protocol through the new login() and starttls()
28 methods.
29
30- A new hmac module implementing keyed hashing for message authentication.
31
Tim Petersb07352e2001-09-08 01:25:47 +000032Tools
33
34Build
35
36C API
37
38New platforms
39
40Tests
41
42Windows
43
44
Tim Petersedc99312001-08-22 21:36:50 +000045What's New in Python 2.2a3?
46===========================
47
48Core
49
Tim Peters9fffa3e2001-09-04 05:14:19 +000050- Conversion of long to float now raises OverflowError if the long is too
51 big to represent as a C double.
52
Tim Peters32f453e2001-09-03 08:35:41 +000053- The 3-argument builtin pow() no longer allows a third non-None argument
54 if either of the first two arguments is a float, or if both are of
55 integer types and the second argument is negative (in which latter case
56 the arguments are converted to float, so this is really the same
57 restriction).
58
Tim Peters5d2b77c2001-09-03 05:47:38 +000059- The builtin dir() now returns more information, and sometimes much
60 more, generally naming all attributes of an object, and all attributes
61 reachable from the object via its class, and from its class's base
62 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
63 an empty list. In 2.2a3,
64
65 >>> dir([])
66 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
67 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
68 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
69 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
70 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
71 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
72 'reverse', 'sort']
73
74 dir(module) continues to return only the module's attributes, though.
75
Tim Petersbdee63f2001-09-02 03:40:59 +000076- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +000077 than raising OverflowError. This is a partial implementation of PEP
78 237. You can use -Wdefault::OverflowWarning to enable a warning for
79 this situation, and -Werror::OverflowWarning to revert to the old
80 OverflowError exception.
81
Guido van Rossum61c345f2001-09-04 03:26:15 +000082- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +000083 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +000084 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
85 -Qold, meaning the / operator has its classic meaning and no
86 warnings are issued. Using -Qwarn issues a run-time warning about
87 all uses of classic division for int and long arguments; -Qwarnall
88 also warns about classic division for float and complex arguments
89 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
90 new division by default, but only in the __main__ module. You can
91 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
92 __main__ module new division, and warns about classic division
93 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +000094
Tim Petersbdee63f2001-09-02 03:40:59 +000095- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +000096 long, float, str, unicode, and tuple. (The types complex, list and
97 dictionary can also be subclassed; this was introduced earlier.)
98 Note that restrictions apply when subclassing immutable built-in
99 types: you can only affect the value of the instance by overloading
100 __new__. You can add mutable attributes, and the subclass instances
101 will have a __dict__ attribute, but you cannot change the "value"
102 (as implemented by the base class) of an immutable subclass instance
103 once it is created.
104
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000105- The dictionary constructor now takes an optional argument, a
106 mapping-like object, and initializes the dictionary from its
107 (key, value) pairs.
108
Tim Petersbdee63f2001-09-02 03:40:59 +0000109- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000110 "cooperative super calls" in a multiple inheritance setting. For an
111 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
112
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000113- A new built-in type, property, has been added. This enables the
114 creation of "properties". These are attributes implemented by
115 getter and setter functions (or only one of these for read-only or
116 write-only attributes), without the need to override __getattr__.
117 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000118
Tim Petersbdee63f2001-09-02 03:40:59 +0000119- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000120 liberalized, to allow leading zeroes. Examples of literals now
121 legal that were SyntaxErrors before:
122
123 00.0 0e3 0100j 07.5 00000000000000000008.
124
Tim Petersbdee63f2001-09-02 03:40:59 +0000125- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000126 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
127
Tim Petersedc99312001-08-22 21:36:50 +0000128Library
129
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000130- telnetlib includes symbolic names for the options, and support for
131 setting an option negotiation callback.
132
Tim Petersa40c7932001-09-05 22:36:56 +0000133- The new C standard no longer requires that math libraries set errno to
134 ERANGE on overflow. For platform libraries that exploit this new
135 freedom, Python's overflow-checking was wholly broken. A new overflow-
136 checking scheme attempts to repair that, but may not be reliable on all
137 platforms (C doesn't seem to provide anything both useful and portable
138 in this area anymore).
139
Martin v. Löwis44f86962001-09-05 13:44:54 +0000140- Asynchronous timeout actions are available through the new class
141 threading.Timer.
142
Tim Peters78526162001-09-05 00:53:45 +0000143- math.log and math.log10 now return sensible results for even huge
144 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
145
Tim Petersbdee63f2001-09-02 03:40:59 +0000146- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000147 currently held. See the docs for the imp module.
148
Tim Petersbdee63f2001-09-02 03:40:59 +0000149- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000150 dumps containing ints written on platforms where Python ints are 8 bytes.
151 When read on a box where Python ints are 4 bytes, such values are
152 converted to Python longs.
153
Tim Petersbdee63f2001-09-02 03:40:59 +0000154- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000155 code objects is no longer allowed. This plugs a security hole.
156
Steve Purcell6091cd62001-09-06 16:05:17 +0000157- unittest.TestResult instances no longer store references to tracebacks
158 generated by test failures. This prevents unexpected dangling references
159 to objects that should be garbage collected between tests.
160
Tim Petersedc99312001-08-22 21:36:50 +0000161Tools
162
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000163- Tools/scripts/fixdiv.py has been added which can be used to fix
164 division operators as per PEP 238.
165
Tim Petersedc99312001-08-22 21:36:50 +0000166Build
167
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000168- If you are an adventurous person using Mac OS X you may want to look at
169 Mac/OSX. There is a Makefile there that will build Python as a real Mac
170 application, which can be used for experimenting with Carbon or Cocoa.
171 Discussion of this on pythonmac-sig, please.
172
Tim Peters7eea37e2001-09-04 22:08:56 +0000173C API
174
175- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000176
Tim Peters9fffa3e2001-09-04 05:14:19 +0000177- Note that PyLong_AsDouble can fail! This has always been true, but no
178 callers checked for it. It's more likely to fail now, because overflow
179 errors are properly detected now. The proper way to check:
180
181 double x = PyLong_AsDouble(some_long_object);
182 if (x == -1.0 && PyErr_Occurred()) {
183 /* The conversion failed. */
184 }
185
Tim Petersbdee63f2001-09-02 03:40:59 +0000186- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000187 compile but will not participate in GC. To upgrade an extension
188 module:
189
190 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000191
Neil Schemenauer4042c692001-08-30 15:38:01 +0000192 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
193 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000194
Neil Schemenauer4042c692001-08-30 15:38:01 +0000195 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
196 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000197
Neil Schemenauer4042c692001-08-30 15:38:01 +0000198 - remove PyGC_HEAD_SIZE from object size calculations
199
200 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
201
Tim Petersbdee63f2001-09-02 03:40:59 +0000202- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000203 These can be used safely to construct string objects from a
204 sprintf-style format string (similar to the format string supported
205 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000206
Tim Petersedc99312001-08-22 21:36:50 +0000207New platforms
208
Tim Petersb7da0902001-09-02 23:01:43 +0000209- Stephen Hansen contributed patches sufficient to get a clean compile
210 under Borland C (Windows), but he reports problems running it and ran
211 out of time to complete the port. Volunteers? Expect a MemoryError
212 when importing the types module; this is probably shallow, and
213 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000214
Tim Petersedc99312001-08-22 21:36:50 +0000215Tests
216
217Windows
218
Tim Peters6e13a562001-09-06 00:32:15 +0000219- Large file support is now enabled on Win32 platforms as well as on
220 Win64. This means that, for example, you can use f.tell() and f.seek()
221 to manipulate files larger than 2 gigabytes (provided you have enough
222 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000223 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
224 filesize limit, and large file support makes no difference there.
225 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
226 NTFS has no practical limit on file size, and files of any size can be
227 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000228
Tim Petersbdee63f2001-09-02 03:40:59 +0000229- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000230 points to command.com (patch from Brian Quinlan).
231
Tim Petersedc99312001-08-22 21:36:50 +0000232
Tim Peters20f51a72001-07-21 02:31:40 +0000233What's New in Python 2.2a2?
234===========================
235
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000236Build
237
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000238- Tim Peters developed a brand new Windows installer using Wise 8.1,
239 generously donated to us by Wise Solutions.
240
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000241- configure supports a new option --enable-unicode, with the values
242 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
243 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000244
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000245- A new configure option --enable-framework builds a Mac OS X framework,
246 which "make frameworkinstall" will install. This provides a starting
247 point for more mac-like functionality, join pythonmac-sig@python.org
248 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000249
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000250- The NeXT platform is no longer supported.
251
252- The `new' module is now statically linked.
253
Tim Peters0afb6092001-08-15 06:06:44 +0000254Tools
255
256- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000257 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000258 the module docstring for details.
259
Tim Peters20f51a72001-07-21 02:31:40 +0000260Tests
261
Tim Peters5e824c32001-08-12 22:25:01 +0000262- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000263 platforms, allowing to give clearer test result output. regrtest
264 also has optional --use/-u switch to run normally disabled tests
265 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000266
Tim Peters20f51a72001-07-21 02:31:40 +0000267- Several new tests in the standard test suite, with special thanks to
268 Nick Mathewson.
269
270Core
271
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000272- The floor division operator // has been added as outlined in PEP
273 238. The / operator still provides classic division (and will until
274 Python 3.0) unless "from __future__ import division" is included, in
275 which case the / operator will provide true division. The operator
276 module provides truediv() and floordiv() functions. Augmented
277 assignment variants are included, as are the equivalent overloadable
278 methods and C API methods. See the PEP for a full discussion:
279 <http://python.sf.net/peps/pep-0238.html>
280
Tim Peters6cd6a822001-08-17 22:11:27 +0000281- Future statements are now effective in simulated interactive shells
282 (like IDLE). This should "just work" by magic, but read Michael
283 Hudson's "Future statements in simulated shells" PEP 264 for full
284 details: <http://python.sf.net/peps/pep-0264.html>.
285
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000286- The type/class unification (PEP 252-253) was integrated into the
287 trunk and is not so tentative any more (the exact specification of
288 some features is still tentative). A lot of work has done on fixing
289 bugs and adding robustness and features (performance still has to
290 come a long way).
291
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000292- Warnings about a mismatch in the Python API during extension import
293 now use the Python warning framework (which makes it possible to
294 write filters for these warnings).
295
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000296- A function's __dict__ (aka func_dict) will now always be a
297 dictionary. It used to be possible to delete it or set it to None,
298 but now both actions raise TypeErrors. It is still legal to set it
299 to a dictionary object. Getting func.__dict__ before any attributes
300 have been assigned now returns an empty dictionary instead of None.
301
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000302- A new command line option, -E, was added which disables the use of
303 all environment variables, or at least those that are specifically
304 significant to Python. Usually those have a name starting with
305 "PYTHON". This was used to fix a problem where the tests fail if
306 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
307 older distribution.
308
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000309Library
310
Tim Peters5e824c32001-08-12 22:25:01 +0000311- New class Differ and new functions ndiff() and restore() in difflib.py.
312 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000313 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000314
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000315- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
316 value using the minimal quoting required for the value; more
317 reliable than using xml.sax.saxutils.escape() for attribute values.
318
319- Readline completion support for cmd.Cmd was added.
320
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000321- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
322
323- Added function threading.BoundedSemaphore()
324
325- Added Ka-Ping Yee's cgitb.py module.
326
327- The `new' module now exposes the CO_xxx flags.
328
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000329New platforms
330
331C API
332
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000333- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
334 which provide a cross-platform implementations for the
335 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
336 the standard sprintf() and vsprintf() C lib APIs, these versions
337 apply bounds checking on the used buffer which enhances protection
338 against buffer overruns.
339
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000340- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000341 and extensions using different Unicode widths is rendered next to
342 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000343 will result in an ImportError. Unicode extensions writers must make
344 sure to check the Unicode width compatibility in their extensions by
345 using at least one of the mangled Unicode APIs in the extension.
346
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000347- Two new flags METH_NOARGS and METH_O are available in method definition
348 tables to simplify implementation of methods with no arguments and a
349 single untyped argument. Calling such methods is more efficient than
350 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
351 deprecated.
352
Tim Petersc1731372001-08-04 08:12:36 +0000353Windows
354
355- "import module" now compiles module.pyw if it exists and nothing else
356 relevant is found.
357
Tim Peters20f51a72001-07-21 02:31:40 +0000358
Guido van Rossum55a78992001-07-17 17:22:32 +0000359What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000360===========================
361
362Core
Tim Petersa814db52001-05-14 07:05:58 +0000363
Tim Peters6d6c1a32001-08-02 04:15:00 +0000364- TENTATIVELY, a large amount of code implementing much of what's
365 described in PEP 252 (Making Types Look More Like Classes) and PEP
366 253 (Subtyping Built-in Types) was added. This will be released
367 with Python 2.2a1. Documentation will be provided separately
368 through http://www.python.org/2.2/. The purpose of releasing this
369 with Python 2.2a1 is to test backwards compatibility. It is
370 possible, though not likely, that a decision is made not to release
371 this code as part of 2.2 final, if any serious backwards
372 incompapatibilities are found during alpha testing that cannot be
373 repaired.
374
Guido van Rossum55a78992001-07-17 17:22:32 +0000375- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000376 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000377 more 'yield' statements. See PEP 255. Since this adds a new
378 keyword to the language, this feature must be enabled by including a
379 future statement: "from __future__ import generators" (see PEP 236).
380 Generators will become a standard feature in a future release
381 (probably 2.3). Without this future statement, 'yield' remains an
382 ordinary identifier, but a warning is issued each time it is used.
383 (These warnings currently don't conform to the warnings framework of
384 PEP 230; we intend to fix this in 2.2a2.)
385
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000386- The UTF-16 codec was modified to be more RFC compliant. It will now
387 only remove BOM characters at the start of the string and then
388 only if running in native mode (UTF-16-LE and -BE won't remove a
389 leading BMO character).
390
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000391- Strings now have a new method .decode() to complement the already
392 existing .encode() method. These two methods provide direct access
393 to the corresponding decoders and encoders of the registered codecs.
394
395 To enhance the usability of the .encode() method, the special
396 casing of Unicode object return values was dropped (Unicode objects
397 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000398
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000399 Both methods will now return whatever the codec in charge of the
400 requested encoding returns as object, e.g. Unicode codecs will
401 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
402 will return u"äöü"). This enables codec writer to create codecs
403 for various simple to use conversions.
404
405 New codecs were added to demonstrate these new features (the .encode()
406 and .decode() columns indicate the type of the returned objects):
407
408 Name | .encode() | .decode() | Description
409 ----------------------------------------------------------------------
410 uu | string | string | UU codec (e.g. for email)
411 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000412 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000413 zlib | string | string | zlib compression
414 hex | string | string | 2-byte hex codec
415 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
416
Mark Hammond2a0af792001-05-14 03:09:36 +0000417- Some operating systems now support the concept of a default Unicode
418 encoding for file system operations. Notably, Windows supports 'mbcs'
419 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000420 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000421 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000422
423 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000424 functions that return filenames (such as os.listdir()) to return Python
425 string objects pre-encoded using the default file system encoding for
426 the platform. As this encoding is likely to be different from Python's
427 default encoding, converting this name to a Unicode object before passing
428 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000429 would attempt to use its default encoding (generally ASCII) rather than
430 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000431
Tim Petersa814db52001-05-14 07:05:58 +0000432 In general, this change simply removes surprises when working with
433 Unicode and the file system, making these operations work as you expect,
434 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000435 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000436
Tim Peters61dff2b2001-05-08 15:43:37 +0000437- Float (and complex) literals in source code were evaluated to full
438 precision only when running from a .py file; the same code loaded from a
439 .pyc (or .pyo) file could suffer numeric differences starting at about the
440 12th significant decimal digit. For example, on a machine with IEEE-754
441 floating arithmetic,
442
443 x = 9007199254740992.0
444 print long(x)
445
446 printed 9007199254740992 if run directly from .py, but 9007199254740000
447 if from a compiled (.pyc or .pyo) file. This was due to marshal using
448 str(float) instead of repr(float) when building code objects. marshal
449 now uses repr(float) instead, which should reproduce floats to full
450 machine precision (assuming the platform C float<->string I/O conversion
451 functions are of good quality).
452
453 This may cause floating-point results to change in some cases, and
454 usually for the better, but may also cause numerically unstable
455 algorithms to break.
456
Tim Peters2f228e72001-05-13 00:19:31 +0000457- The implementation of dicts suffers fewer collisions, which has speed
458 benefits. However, the order in which dict entries appear in dict.keys(),
459 dict.values() and dict.items() may differ from previous releases for a
460 given dict. Nothing is defined about this order, so no program should
461 rely on it. Nevertheless, it's easy to write test cases that rely on the
462 order by accident, typically because of printing the str() or repr() of a
463 dict to an "expected results" file. See Lib/test/test_support.py's new
464 sortdict(dict) function for a simple way to display a dict in sorted
465 order.
466
Tim Peters7a3bfc32001-06-12 01:22:22 +0000467- Many other small changes to dicts were made, resulting in faster
468 operation along the most common code paths.
469
Guido van Rossum10315822001-05-01 20:54:30 +0000470- Dictionary objects now support the "in" operator: "x in dict" means
471 the same as dict.has_key(x).
472
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000473- The update() method of dictionaries now accepts generic mapping
474 objects. Specifically the argument object must support the .keys()
475 and __getitem__() methods. This allows you to say, for example,
476 {}.update(UserDict())
477
Guido van Rossum10315822001-05-01 20:54:30 +0000478- Iterators were added; this is a generalized way of providing values
479 to a for loop. See PEP 234. There's a new built-in function iter()
480 to return an iterator. There's a new protocol to get the next value
481 from an iterator using the next() method (in Python) or the
482 tp_iternext slot (in C). There's a new protocol to get iterators
483 using the __iter__() method (in Python) or the tp_iter slot (in C).
484 Iterating (i.e. a for loop) over a dictionary generates its keys.
485 Iterating over a file generates its lines.
486
Tim Petersf553f892001-05-01 20:45:31 +0000487- The following functions were generalized to work nicely with iterator
488 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000489 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000490 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
491 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000492 join() method of strings
493 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000494 'x in y' and 'x not in y' (PySequence_Contains() in C API)
495 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000496 right-hand side of assignment statements with multiple targets, such as
497 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000498
Tim Petersd85e1022001-05-11 21:51:48 +0000499- Accessing module attributes is significantly faster (for example,
500 random.random or os.path or yourPythonModule.yourAttribute).
501
Tim Peterse63415e2001-05-08 04:38:29 +0000502- Comparing dictionary objects via == and != is faster, and now works even
503 if the keys and values don't support comparisons other than ==.
504
Tim Peters95bf9392001-05-10 08:32:44 +0000505- Comparing dictionaries in ways other than == and != is slower: there were
506 insecurities in the dict comparison implementation that could cause Python
507 to crash if the element comparison routines for the dict keys and/or
508 values mutated the dicts. Making the code bulletproof slowed it down.
509
Tim Peterseb28ef22001-06-02 05:27:19 +0000510- Collisions in dicts are resolved via a new approach, which can help
511 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000512 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000513 faster now. Thanks to Christian Tismer for pointing out the cause and
514 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000515
Tim Peters52e155e2001-06-16 05:42:57 +0000516- repr() is much faster for large containers (dict, list, tuple).
517
518
Tim Petersa814db52001-05-14 07:05:58 +0000519Library
520
Fred Drake960fdf92001-07-20 18:38:26 +0000521- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
522 were added to the string module. These a locale-indenpendent
523 constants, unlike letters, lowercase, and uppercase. These are now
524 use in appropriate locations in the standard library.
525
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000526- The flags used in dlopen calls can now be configured using
527 sys.setdlopenflags and queried using sys.getdlopenflags.
528
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000529- Fredrik Lundh's xmlrpclib is now a standard library module. This
530 provides full client-side XML-RPC support. In addition,
531 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
532 one asyncore-based). Thanks to Eric Raymond for the documentation.
533
Guido van Rossum643d3912001-07-05 14:46:25 +0000534- The xrange() object is simplified: it no longer supports slicing,
535 repetition, comparisons, efficient 'in' checking, the tolist()
536 method, or the start, stop and step attributes. See PEP 260.
537
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000538- A new function fnmatch.filter to filter lists of file names was added.
539
Barry Warsawffd674d2001-05-22 16:00:10 +0000540- calendar.py uses month and day names based on the current locale.
541
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000542- strop is now *really* obsolete (this was announced before with 1.6),
543 and issues DeprecationWarning when used (except for the four items
544 that are still imported into string.py).
545
Tim Petersa814db52001-05-14 07:05:58 +0000546- Cookie.py now sorts key+value pairs by key in output strings.
547
548- pprint.isrecursive(object) didn't correctly identify recursive objects.
549 Now it does.
550
Tim Peters95b3f782001-05-14 18:39:41 +0000551- pprint functions now much faster for large containers (tuple, list, dict).
552
Tim Peters7b9542a2001-06-10 23:40:19 +0000553- New 'q' and 'Q' format codes in the struct module, corresponding to C
554 types "long long" and "unsigned long long" (on Windows, __int64). In
555 native mode, these can be used only when the platform C compiler supports
556 these types (when HAVE_LONG_LONG is #define'd by the Python config
557 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000558 In standard mode, 'q' and 'Q' are supported on all platforms, and are
559 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000560
Guido van Rossum83213cc2001-06-12 16:48:52 +0000561- The site module installs a new built-in function 'help' that invokes
562 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
563 it displays a message reminding the user to use 'help()' or
564 'help(object)'.
565
Tim Petersa814db52001-05-14 07:05:58 +0000566Tests
567
568- New test_mutants.py runs dict comparisons where the key and value
569 comparison operators mutute the dicts randomly during comparison. This
570 rapidly causes Python to crash under earlier releases (not for the faint
571 of heart: it can also cause Win9x to freeze or reboot!).
572
573- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000574 pprint.isreadable() return sensible results. Also verifies that simple
575 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000576
Tim Peters4324aa32001-05-28 22:30:08 +0000577C API
578
579- Removed the unused last_is_sticky argument from the internal
580 _PyTuple_Resize(). If this affects you, you were cheating.
581
582
Guido van Rossum55a78992001-07-17 17:22:32 +0000583======================================================================
584
585
Guido van Rossumffe13be2001-04-16 18:46:45 +0000586What's New in Python 2.1 (final)?
587=================================
588
589We only changed a few things since the last release candidate, all in
590Python library code:
591
592- A bug in the locale module was fixed that affected locales which
593 define no grouping for numeric formatting.
594
595- A few bugs in the weakref module's implementations of weak
596 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
597 and the test suite was updated to check for these bugs.
598
599- An old bug in the os.path.walk() function (introduced in Python
600 2.0!) was fixed: a non-existent file would cause an exception
601 instead of being ignored.
602
603- Fixed a few bugs in the new symtable module found by Neil Norwitz's
604 PyChecker.
605
606
Guido van Rossum5b08f132001-04-16 02:05:23 +0000607What's New in Python 2.1c2?
608===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000609
Guido van Rossum5b08f132001-04-16 02:05:23 +0000610A flurry of small changes, and one showstopper fixed in the nick of
611time made it necessary to release another release candidate. The list
612here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000613
Guido van Rossum5b08f132001-04-16 02:05:23 +0000614Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000615
Guido van Rossum5b08f132001-04-16 02:05:23 +0000616- Tim discovered a nasty bug in the dictionary code, caused by
617 PyDict_Next() calling dict_resize(), and the GC code's use of
618 PyDict_Next() violating an assumption in dict_items(). This was
619 fixed with considerable amounts of band-aid, but the net effect is a
620 saner and more robust implementation.
621
622- Made a bunch of symbols static that were accidentally global.
623
624Build and Ports
625
626- The setup.py script didn't check for a new enough version of zlib
627 (1.1.3 is needed). Now it does.
628
629- Changed "make clean" target to also remove shared libraries.
630
631- Added a more general warning about the SGI Irix optimizer to README.
632
633Library
634
635- Fix a bug in urllib.basejoin("http://host", "../file.html") which
636 omitted the slash between host and file.html.
637
638- The mailbox module's _Mailbox class contained a completely broken
639 and undocumented seek() method. Ripped it out.
640
641- Fixed a bunch of typos in various library modules (urllib2, smtpd,
642 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
643
644- Fixed a few last-minute bugs in unittest.
645
646Extensions
647
648- Reverted the patch to the OpenSSL code in socketmodule.c to support
649 RAND_status() and the EGD, and the subsequent patch that tried to
650 fix it for pre-0.9.5 versions; the problem with the patch is that on
651 some systems it issues a warning whenever socket is imported, and
652 that's unacceptable.
653
654Tests
655
656- Fixed the pickle tests to work with "import test.test_pickle".
657
658- Tweaked test_locale.py to actually run the test Windows.
659
660- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
661 not "wb" (which is not a valid mode at all).
662
663- Fix pstats browser crashes. Import readline if it exists to make
664 the user interface nicer.
665
666- Add "import thread" to the top of test modules that import the
667 threading module (test_asynchat and test_threadedtempfile). This
668 prevents test failures caused by a broken threading module resulting
669 from a previously caught failed import.
670
671- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
672 needed on some platforms (e.g. Solaris 8) when the tests are run
673 twice in succession.
674
675- Skip rather than fail test_sunaudiodev if no audio device is found.
676
677
678What's New in Python 2.1c1?
679===========================
680
681This list was significantly updated when 2.1c2 was released; the 2.1c1
682release didn't mention most changes that were actually part of 2.1c1:
683
684Legal
685
686- Copyright was assigned to the Python Software Foundation (PSF) and a
687 PSF license (very similar to the CNRI license) was added.
688
689- The CNRI copyright notice was updated to include 2001.
690
691Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000692
Guido van Rossumc9932722001-04-12 02:31:27 +0000693- After a public outcry, assignment to __debug__ is no longer illegal;
694 instead, a warning is issued. It will become illegal in 2.2.
695
Guido van Rossum5b08f132001-04-16 02:05:23 +0000696- Fixed a core dump with "%#x" % 0, and changed the semantics so that
697 "%#x" now always prepends "0x", even if the value is zero.
698
699- Fixed some nits in the bytecode compiler.
700
701- Fixed core dumps when calling certain kinds of non-functions.
702
703- Fixed various core dumps caused by reference count bugs.
704
705Build and Ports
706
707- Use INSTALL_SCRIPT to install script files.
708
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000709- New port: SCO Unixware 7, by Billy G. Allie.
710
Guido van Rossum5b08f132001-04-16 02:05:23 +0000711- Updated RISCOS port.
712
713- Updated BeOS port and notes.
714
715- Various other porting problems resolved.
716
717Library
718
719- The TERMIOS and SOCKET modules are now truly obsolete and
720 unnecessary. Their symbols are incorporated in the termios and
721 socket modules.
722
723- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
724 better tests for pickling.
725
726- threading: make Condition.wait() robust against KeyboardInterrupt.
727
728- zipfile: add support to zipfile to support opening an archive
729 represented by an open file rather than a file name. Fix bug where
730 the archive was not properly closed. Fixed a bug in this bugfix
731 where flush() was called for a read-only file.
732
733- imputil: added an uninstall() method to the ImportManager.
734
735- Canvas: fixed bugs in lower() and tkraise() methods.
736
737- SocketServer: API change (added overridable close_request() method)
738 so that the TCP server can explicitly close the request.
739
740- pstats: Eric Raymond added a simple interactive statistics browser,
741 invoked when the module is run as a script.
742
743- locale: fixed a problem in format().
744
745- webbrowser: made it work when the BROWSER environment variable has a
746 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
747 KDE 2. Fixed some other nits.
748
749- unittest: changes to allow using a different exception than
750 AssertionError, and added a few more function aliases. Some other
751 small changes.
752
753- urllib, urllib2: fixed redirect problems and a coupleof other nits.
754
755- asynchat: fixed a critical bug in asynchat that slipped through the
756 2.1b2 release. Fixed another rare bug.
757
758- Fix some unqualified except: clauses (always a bad code example).
759
760XML
761
762- pyexpat: new API get_version_string().
763
764- Fixed some minidom bugs.
765
766Extensions
767
768- Fixed a core dump in _weakref. Removed the weakref.mapping()
769 function (it adds nothing to the API).
770
771- Rationalized the use of header files in the readline module, to make
772 it compile (albeit with some warnings) with the very recent readline
773 4.2, without breaking for earlier versions.
774
775- Hopefully fixed a buffering problem in linuxaudiodev.
776
777- Attempted a fix to make the OpenSSL support in the socket module
778 work again with pre-0.9.5 versions of OpenSSL.
779
780Tests
781
782- Added a test case for asynchat and asyncore.
783
784- Removed coupling between tests where one test failing could break
785 another.
786
787Tools
788
789- Ping added an interactive help browser to pydoc, fixed some nits
790 in the rest of the pydoc code, and added some features to his
791 inspect module.
792
793- An updated python-mode.el version 4.1 which integrates Ken
794 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
795 much nicer in XEmacs and Emacs. When stepping through your program
796 with pdb, in either the shell window or the *Python* window, the
797 source file and line will be tracked by an arrow. Very cool!
798
799- IDLE: syntax warnings in interactive mode are changed into errors.
800
801- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000802 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000803
804- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000805
Barry Warsaw11e89c72001-04-11 20:37:57 +0000806
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000807What's New in Python 2.1 beta 2?
808================================
809
Guido van Rossum053ae352001-03-22 14:17:21 +0000810(Unlisted are many fixed bugs, more documentation, etc.)
811
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000812Core language, builtins, and interpreter
813
Guido van Rossum053ae352001-03-22 14:17:21 +0000814- The nested scopes work (enabled by "from __future__ import
815 nested_scopes") is completed; in particular, the future now extends
816 into code executed through exec, eval() and execfile(), and into the
817 interactive interpreter.
818
819- When calling a base class method (e.g. BaseClass.__init__(self)),
820 this is now allowed even if self is not strictly spoken a class
821 instance (e.g. when using metaclasses or the Don Beaudry hook).
822
823- Slice objects are now comparable but not hashable; this prevents
824 dict[:] from being accepted but meaningless.
825
826- Complex division is now calculated using less braindead algorithms.
827 This doesn't change semantics except it's more likely to give useful
828 results in extreme cases. Complex repr() now uses full precision
829 like float repr().
830
831- sgmllib.py now calls handle_decl() for simple <!...> declarations.
832
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000833- It is illegal to assign to the name __debug__, which is set when the
834 interpreter starts. It is effectively a compile-time constant.
835
836- A warning will be issued if a global statement for a variable
837 follows a use or assignment of that variable.
838
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000839Standard library
840
Guido van Rossum053ae352001-03-22 14:17:21 +0000841- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
842 inspired by JUnit), is now part of the standard library. You now
843 have a choice of two testing frameworks: unittest requires you to
844 write testcases as separate code, doctest gathers them from
845 docstrings. Both approaches have their advantages and
846 disadvantages.
847
848- A new module Tix was added, which wraps the Tix extension library
849 for Tk. With that module, it is not necessary to statically link
850 Tix with _tkinter, since Tix will be loaded with Tcl's "package
851 require" command. See Demo/tix/.
852
853- tzparse.py is now obsolete.
854
855- In gzip.py, the seek() and tell() methods are removed -- they were
856 non-functional anyway, and it's better if callers can test for their
857 existence with hasattr().
858
859Python/C API
860
861- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
862 that's already in the dictionary during a PyDict_Next() iteration.
863 This used to fail occasionally when a dictionary resize operation
864 could be triggered that would rehash all the keys. All other
865 modifications to the dictionary are still off-limits during a
866 PyDict_Next() iteration!
867
868- New extended APIs related to passing compiler variables around.
869
870- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
871 implement isinstance() and issubclass().
872
873- Py_BuildValue() now has a "D" conversion to create a Python complex
874 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000875
Fred Drake4e262a92001-03-22 18:26:47 +0000876- Extensions types which support weak references must now set the
877 field allocated for the weak reference machinery to NULL themselves;
878 this is done to avoid the cost of checking each object for having a
879 weakly referencable type in PyObject_INIT(), since most types are
880 not weakly referencable.
881
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000882- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
883 free variables and cell variables to and from the frame's f_locals.
884
885- Variants of several functions defined in pythonrun.h have been added
886 to support the nested_scopes future statement. The variants all end
887 in Flags and take an extra argument, a PyCompilerFlags *; examples:
888 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
889 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000890 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000891
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000892Distutils
893
894- the sdist command now writes a PKG-INFO file, as described in PEP 241,
895 into the release tree.
896
Tim Peters0e57abf2001-05-02 07:39:38 +0000897- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000898 (an uninstaller, more customization of the installer's display)
899
900- from Jack Jansen: added Mac-specific code to generate a dialog for
901 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000902 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000903 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000904
905- added 'platforms' and 'keywords' to the set of metadata that can be
906 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000907
908- applied patches from Jason Tishler to make the compiler class work with
909 Cygwin.
910
911
Tim Peters2fe289a2001-03-01 22:19:38 +0000912What's New in Python 2.1 beta 1?
913================================
Tim Petersd66595f2001-02-04 03:09:53 +0000914
915Core language, builtins, and interpreter
916
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000917- Following an outcry from the community about the amount of code
918 broken by the nested scopes feature introduced in 2.1a2, we decided
919 to make this feature optional, and to wait until Python 2.2 (or at
920 least 6 months) to make it standard. The option can be enabled on a
921 per-module basis by adding "from __future__ import nested_scopes" at
922 the beginning of a module (before any other statements, but after
923 comments and an optional docstring). See PEP 236 (Back to the
924 __future__) for a description of the __future__ statement. PEP 227
925 (Statically Nested Scopes) has been updated to reflect this change,
926 and to clarify the semantics in a number of endcases.
927
928- The nested scopes code, when enabled, has been hardened, and most
929 bugs and memory leaks in it have been fixed.
930
931- Compile-time warnings are now generated for a number of conditions
932 that will break or change in meaning when nested scopes are enabled:
933
934 - Using "from...import *" or "exec" without in-clause in a function
935 scope that also defines a lambda or nested function with one or
936 more free (non-local) variables. The presence of the import* or
937 bare exec makes it impossible for the compiler to determine the
938 exact set of local variables in the outer scope, which makes it
939 impossible to determine the bindings for free variables in the
940 inner scope. To avoid the warning about import *, change it into
941 an import of explicitly name object, or move the import* statement
942 to the global scope; to avoid the warning about bare exec, use
943 exec...in... (a good idea anyway -- there's a possibility that
944 bare exec will be deprecated in the future).
945
946 - Use of a global variable in a nested scope with the same name as a
947 local variable in a surrounding scope. This will change in
948 meaning with nested scopes: the name in the inner scope will
949 reference the variable in the outer scope rather than the global
950 of the same name. To avoid the warning, either rename the outer
951 variable, or use a global statement in the inner function.
952
Neil Schemenauera35c6882001-02-27 04:45:05 +0000953- An optional object allocator has been included. This allocator is
954 optimized for Python objects and should be faster and use less memory
955 than the standard system allocator. It is not enabled by default
956 because of possible thread safety problems. The allocator is only
957 protected by the Python interpreter lock and it is possible that some
958 extension modules require a thread safe allocator. The object
959 allocator can be enabled by providing the "--with-pymalloc" option to
960 configure.
961
Tim Petersd66595f2001-02-04 03:09:53 +0000962Standard library
963
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000964- pyexpat now detects the expat version if expat.h defines it. A
965 number of additional handlers are provided, which are only available
966 since expat 1.95. In addition, the methods SetParamEntityParsing and
967 GetInputContext of Parser objects are available with 1.95.x
968 only. Parser objects now provide the ordered_attributes and
969 specified_attributes attributes. A new module expat.model was added,
970 which offers a number of additional constants if 1.95.x is used.
971
972- xml.dom offers the new functions registerDOMImplementation and
973 getDOMImplementation.
974
975- xml.dom.minidom offers a toprettyxml method. A number of DOM
976 conformance issues have been resolved. In particular, Element now
977 has an hasAttributes method, and the handling of namespaces was
978 improved.
979
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000980- Ka-Ping Yee contributed two new modules: inspect.py, a module for
981 getting information about live Python code, and pydoc.py, a module
982 for interactively converting docstrings to HTML or text.
983 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000984 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000985 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
986 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000987
Tim Peters1eff7962001-03-01 02:31:33 +0000988- New library module difflib.py, primarily packaging the SequenceMatcher
989 class at the heart of the popular ndiff.py file-comparison tool.
990
991- doctest.py (a framework for verifying Python code examples in docstrings)
992 is now part of the std library.
993
Tim Petersd66595f2001-02-04 03:09:53 +0000994Windows changes
995
Guido van Rossume3955a82001-03-02 14:05:59 +0000996- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
997 small GUI that lets you browse the module docstrings using your
998 default web browser.
999
Tim Peters1eff7962001-03-01 02:31:33 +00001000- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1001 Platforms) is implemented. See
1002
1003 http://python.sourceforge.net/peps/pep-0235.html
1004
1005 for full details, especially the "Current Lower-Left Semantics" section.
1006 The new Windows import rules are simpler than before:
1007
1008 A. If the PYTHONCASEOK environment variable exists, same as
1009 before: silently accept the first case-insensitive match of any
1010 kind; raise ImportError if none found.
1011
1012 B. Else search sys.path for the first case-sensitive match; raise
1013 ImportError if none found.
1014
1015 The same rules have been implented on other platforms with case-
1016 insensitive but case-preserving filesystems too (including Cygwin, and
1017 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001018
Tim Peters25a9ce32001-02-19 07:06:36 +00001019- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1020 what it's supposed to do (and does do under NT and 2000) via direct
1021 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001022 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001023 all Win9x systems before.
1024
Tim Peters1eff7962001-03-01 02:31:33 +00001025- Build: Subproject _test (effectively) renamed to _testcapi.
1026
Tim Peters2fe289a2001-03-01 22:19:38 +00001027New platforms
1028
1029- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1030 Thanks to Steven Majewski!
1031
1032- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1033 Tishler!
1034
Guido van Rossum9089b272001-03-02 06:49:50 +00001035- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1036 Schwertberger! See RISCOS/README for more information -- it seems
1037 that because of the bizarre filename conventions on RISCOS, no port
1038 to that platform is easy. Note that the new variable os.endsep is
1039 silently supported in order to make life easier on this platform,
1040 but we don't advertise it because it's not worth for most folks to
1041 care about RISCOS portability.
1042
Tim Peters25a9ce32001-02-19 07:06:36 +00001043
Tim Petersd7b5e882001-01-25 03:36:26 +00001044What's New in Python 2.1 alpha 2?
1045=================================
Tim Peters40ead762001-01-27 05:35:26 +00001046
Tim Petersd7b5e882001-01-25 03:36:26 +00001047Core language, builtins, and interpreter
1048
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001049- Scopes nest. If a name is used in a function or class, but is not
1050 local, the definition in the nearest enclosing function scope will
1051 be used. One consequence of this change is that lambda statements
1052 could reference variables in the namespaces where the lambda is
1053 defined. In some unusual cases, this change will break code.
1054
1055 In all previous version of Python, names were resolved in exactly
1056 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001057 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001058 function A is defined within a function B, the names bound in B are
1059 not visible in A. The new rules make names bound in B visible in A,
1060 unless A contains a name binding that hides the binding in B.
1061
1062 Section 4.1 of the reference manual describes the new scoping rules
1063 in detail. The test script in Lib/test/test_scope.py demonstrates
1064 some of the effects of the change.
1065
1066 The new rules will cause existing code to break if it defines nested
1067 functions where an outer function has local variables with the same
1068 name as globals or builtins used by the inner function. Example:
1069
1070 def munge(str):
1071 def helper(x):
1072 return str(x)
1073 if type(str) != type(''):
1074 str = helper(str)
1075 return str.strip()
1076
1077 Under the old rules, the name str in helper() is bound to the
1078 builtin function str(). Under the new rules, it will be bound to
1079 the argument named str and an error will occur when helper() is
1080 called.
1081
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001082- The compiler will report a SyntaxError if "from ... import *" occurs
1083 in a function or class scope. The language reference has documented
1084 that this case is illegal, but the compiler never checked for it.
1085 The recent introduction of nested scope makes the meaning of this
1086 form of name binding ambiguous. In a future release, the compiler
1087 may allow this form when there is no possibility of ambiguity.
1088
Tim Peters40ead762001-01-27 05:35:26 +00001089- repr(string) is easier to read, now using hex escapes instead of octal,
1090 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1091
1092 >>> "\texample \r\n" + chr(0) + chr(255)
1093 '\texample \r\n\x00\xff' # in 2.1
1094 '\011example \015\012\000\377' # in 2.0
1095
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001096- Functions are now compared and hashed by identity, not by value, since
1097 the func_code attribute is writable.
1098
Fred Drakefb9d7122001-02-01 20:00:40 +00001099- Weak references (PEP 205) have been added. This involves a few
1100 changes in the core, an extension module (_weakref), and a Python
1101 module (weakref). The weakref module is the public interface. It
1102 includes support for "explicit" weak references, proxy objects, and
1103 mappings with weakly held values.
1104
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001105- A 'continue' statement can now appear in a try block within the body
1106 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001107 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001108
Tim Petersd7b5e882001-01-25 03:36:26 +00001109Standard library
1110
Barry Warsaw30dbd142001-01-31 22:14:01 +00001111- mailbox.py now has a new class, PortableUnixMailbox which is
1112 identical to UnixMailbox but uses a more portable scheme for
1113 determining From_ separators. Also, the constructors for all the
1114 classes in this module have a new optional `factory' argument, which
1115 is a callable used when new message classes must be instantiated by
1116 the next() method.
1117
Tim Petersd7b5e882001-01-25 03:36:26 +00001118- random.py is now self-contained, and offers all the functionality of
1119 the now-deprecated whrandom.py. See the docs for details. random.py
1120 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001121 and restoring the internal state of the generator; and jumpahead(n),
1122 for quickly forcing the internal state to be the same as if n calls to
1123 random() had been made. The latter is particularly useful for multi-
1124 threaded programs, creating one instance of the random.Random() class for
1125 each thread, then using .jumpahead() to force each instance to use a
1126 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001127
Tim Peters0de88fc2001-02-01 04:59:18 +00001128- random.py's seed() function is new. For bit-for-bit compatibility with
1129 prior releases, use the whseed function instead. The new seed function
1130 addresses two problems: (1) The old function couldn't produce more than
1131 about 2**24 distinct internal states; the new one about 2**45 (the best
1132 that can be done in the Wichmann-Hill generator). (2) The old function
1133 sometimes produced identical internal states when passed distinct
1134 integers, and there was no simple way to predict when that would happen;
1135 the new one guarantees to produce distinct internal states for all
1136 arguments in [0, 27814431486576L).
1137
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001138- The socket module now supports raw packets on Linux. The socket
1139 family is AF_PACKET.
1140
Tim Peters9ea17ac2001-02-02 05:57:15 +00001141- test_capi.py is a start at running tests of the Python C API. The tests
1142 are implemented by the new Modules/_testmodule.c.
1143
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001144- A new extension module, _symtable, provides provisional access to the
1145 internal symbol table used by the Python compiler. A higher-level
1146 interface will be added on top of _symtable in a future release.
1147
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001148- Removed the obsolete soundex module.
1149
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001150- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1151 the isSameNode method; NamedNodeMap the get method.
1152
1153- xml.sax.expatreader supports the lexical handler property; it
1154 generates comment, startCDATA, and endCDATA events.
1155
Tim Petersee826f82001-01-31 19:39:44 +00001156Windows changes
1157
1158- Build procedure: the zlib project is built in a different way that
1159 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001160 the zlib binary used. See PCbuild\readme.txt for details. Your old
1161 zlib-related directories can be deleted; you'll need to download fresh
1162 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001163
Tim Peters9ea17ac2001-02-02 05:57:15 +00001164- Build: New subproject _test for the benefit of test_capi.py (see above).
1165
Tim Petersb16c56f2001-02-02 21:24:51 +00001166- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1167 interface to some Python compiler internals).
1168
1169- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001170 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001171
Tim Petersa3a3a032000-11-30 05:22:44 +00001172What's New in Python 2.1 alpha 1?
1173=================================
1174
1175Core language, builtins, and interpreter
1176
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001177- There is a new Unicode companion to the PyObject_Str() API
1178 called PyObject_Unicode(). It behaves in the same way as the
1179 former, but assures that the returned value is an Unicode object
1180 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001181
Guido van Rossumf98eda02001-01-17 15:54:45 +00001182- The comparison operators support "rich comparison overloading" (PEP
1183 207). C extension types can provide a rich comparison function in
1184 the new tp_richcompare slot in the type object. The cmp() function
1185 and the C function PyObject_Compare() first try the new rich
1186 comparison operators before trying the old 3-way comparison. There
1187 is also a new C API PyObject_RichCompare() (which also falls back on
1188 the old 3-way comparison, but does not constrain the outcome of the
1189 rich comparison to a Boolean result).
1190
1191 The rich comparison function takes two objects (at least one of
1192 which is guaranteed to have the type that provided the function) and
1193 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1194 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1195 object, which may be NotImplemented (in which case the tp_compare
1196 slot function is used as a fallback, if defined).
1197
1198 Classes can overload individual comparison operators by defining one
1199 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001200 __ge__. There are no explicit "reflected argument" versions of
1201 these; instead, __lt__ and __gt__ are each other's reflection,
1202 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1203 reflection (similar at the C level). No other implications are
1204 made; in particular, Python does not assume that == is the Boolean
1205 inverse of !=, or that < is the Boolean inverse of >=. This makes
1206 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001207
1208 Classes or types that want to implement (in)equality tests but not
1209 the ordering operators (i.e. unordered types) should implement ==
1210 and !=, and raise an error for the ordering operators.
1211
Guido van Rossuma88479f2001-01-18 14:28:08 +00001212 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001213 Boolean; e.g. a matrix type might want to return a matrix of bits
1214 for A < B, giving elementwise comparisons. Such types should ensure
1215 that any interpretation of their value in a Boolean context raises
1216 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1217 at the C level) to always raise an exception.
1218
Guido van Rossuma88479f2001-01-18 14:28:08 +00001219- Complex numbers use rich comparisons to define == and != but raise
1220 an exception for <, <=, > and >=. Unfortunately, this also means
1221 that cmp() of two complex numbers raises an exception when the two
1222 numbers differ. Since it is not mathematically meaningful to compare
1223 complex numbers except for equality, I hope that this doesn't break
1224 too much code.
1225
Tim Peters3389f192001-02-18 08:48:49 +00001226- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001227 not defined by the language, other than that it's arbitrary but
1228 consistent (see the Reference Manual). An implementation detail changed
1229 in 2.1a1 such that None now compares less than any other object. Code
1230 relying on this new behavior (like code that relied on the previous
1231 behavior) does so at its own risk.
1232
Barry Warsaw573b5412001-01-15 20:43:18 +00001233- Functions and methods now support getting and setting arbitrarily
1234 named attributes (PEP 232). Functions have a new __dict__
1235 (a.k.a. func_dict) which hold the function attributes. Methods get
1236 and set attributes on their underlying im_func. It is a TypeError
1237 to set an attribute on a bound method.
1238
Guido van Rossum051e3352001-01-15 19:11:10 +00001239- The xrange() object implementation has been improved so that
1240 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1241 limitation that in this case len(xrange(sys.maxint)) can't be
1242 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1243 work fine as long as the index i doesn't actually reach 2**31.
1244 (Python uses regular ints for sequence and string indices; fixing
1245 that is much more work.)
1246
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001247- Two changes to from...import:
1248
Guido van Rossumba381232001-02-03 15:06:40 +00001249 1) "from M import X" now works even if (after loading module M)
1250 sys.modules['M'] is not a real module; it's basically a getattr()
1251 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001252
1253 2) "from M import *" now looks for M.__all__ to decide which names to
1254 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1255 filters out names starting with '_' as before. Whether or not
1256 __all__ exists, there's no restriction on the type of M.
1257
Guido van Rossumf61f1662001-01-10 20:13:55 +00001258- File objects have a new method, xreadlines(). This is the fastest
1259 way to iterate over all lines in a file:
1260
1261 for line in file.xreadlines():
1262 ...do something to line...
1263
1264 See the xreadlines module (mentioned below) for how to do this for
1265 other file-like objects.
1266
1267- Even if you don't use file.xreadlines(), you may expect a speedup on
1268 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001269 quite a bit in platform-specific ways: on systems (like Linux) that
1270 support flockfile(), getc_unlocked(), and funlockfile(), those are
1271 used by default. On systems (like Windows) without getc_unlocked(),
1272 a complicated (but still thread-safe) method using fgets() is used by
1273 default.
1274
Tim Petersd52269b2001-01-25 06:23:18 +00001275 You can force use of the fgets() method by #define'ing
1276 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001277 getc_unlocked()).
1278
Tim Petersd52269b2001-01-25 06:23:18 +00001279 You can force fgets() not to be used by #define'ing
1280 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001281 test_bufio.py fails -- and let us know if it does!).
1282
1283- In addition, the fileinput module, while still slower than the other
1284 methods on most platforms, has been sped up too, by using
1285 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001286
1287- Support for run-time warnings has been added, including a new
1288 command line option (-W) to specify the disposition of warnings.
1289 See the description of the warnings module below.
1290
1291- Extensive changes have been made to the coercion code. This mostly
1292 affects extension modules (which can now implement mixed-type
1293 numerical operators without having to use coercion), but
1294 occasionally, in boundary cases the coercion semantics have changed
1295 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001296 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001297 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001298 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001299
Guido van Rossumf98eda02001-01-17 15:54:45 +00001300- In connection with the coercion changes, a new built-in singleton
1301 object, NotImplemented is defined. This can be returned for
1302 operations that wish to indicate they are not implemented for a
1303 particular combination of arguments. From C, this is
1304 Py_NotImplemented.
1305
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001306- The interpreter accepts now bytecode files on the command line even
1307 if they do not have a .pyc or .pyo extension. On Linux, after executing
1308
Martin v. Löwise214baa2001-02-04 22:37:56 +00001309import imp,sys,string
1310magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1311reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1312open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001313
1314 any byte code file can be used as an executable (i.e. as an argument
1315 to execve(2)).
1316
Tim Peters9940b802000-12-01 07:59:35 +00001317- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001318 character. In 1.6 and earlier, they never produced a sign,
1319 and raised an error if the value of the long was too large
1320 to fit in a Python int. In 2.0, they produced a sign if and
1321 only if too large to fit in an int. This was inconsistent
1322 across platforms (because the size of an int varies across
1323 platforms), and inconsistent with hex() and oct(). Example:
1324
1325 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001326 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001327 'ffffffbe' # in 2.0 and before, on 32-bit machines
1328 >>> hex(-0x42L)
1329 '-0x42L' # in all versions of Python
1330
Tim Peters9940b802000-12-01 07:59:35 +00001331 The behavior of %d formats for negative Python longs remains
1332 the same as in 2.0 (although in 1.6 and before, they raised
1333 an error if the long didn't fit in a Python int).
1334
1335 %u formats don't make sense for Python longs, but are allowed
1336 and treated the same as %d in 2.1. In 2.0, a negative long
1337 formatted via %u produced a sign if and only if too large to
1338 fit in an int. In 1.6 and earlier, a negative long formatted
1339 via %u raised an error if it was too big to fit in an int.
1340
Guido van Rossum3661d392000-12-12 22:10:31 +00001341- Dictionary objects have an odd new method, popitem(). This removes
1342 an arbitrary item from the dictionary and returns it (in the form of
1343 a (key, value) pair). This can be useful for algorithms that use a
1344 dictionary as a bag of "to do" items and repeatedly need to pick one
1345 item. Such algorithms normally end up running in quadratic time;
1346 using popitem() they can usually be made to run in linear time.
1347
Tim Peters36cdad12000-12-29 02:06:45 +00001348Standard library
1349
Thomas Woutersfe385252001-01-19 23:16:56 +00001350- In the time module, the time argument to the functions strftime,
1351 localtime, gmtime, asctime and ctime is now optional, defaulting to
1352 the current time (in the local timezone).
1353
Guido van Rossumda91f222001-01-15 16:36:08 +00001354- The ftplib module now defaults to passive mode, which is deemed a
1355 more useful default given that clients are often inside firewalls
1356 these days. Note that this could break if ftplib is used to connect
1357 to a *server* that is inside a firewall, from outside; this is
1358 expected to be a very rare situation. To fix that, you can call
1359 ftp.set_pasv(0).
1360
Martin v. Löwis10a27872001-01-13 09:54:41 +00001361- The module site now treats .pth files not only for path configuration,
1362 but also supports extensions to the initialization code: Lines starting
1363 with import are executed.
1364
Guido van Rossumf61f1662001-01-10 20:13:55 +00001365- There's a new module, warnings, which implements a mechanism for
1366 issuing and filtering warnings. There are some new built-in
1367 exceptions that serve as warning categories, and a new command line
1368 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1369 turns warnings into errors). warnings.warn(message[, category])
1370 issues a warning message; this can also be called from C as
1371 PyErr_Warn(category, message).
1372
1373- A new module xreadlines was added. This exports a single factory
1374 function, xreadlines(). The intention is that this code is the
1375 absolutely fastest way to iterate over all lines in an open
1376 file(-like) object:
1377
1378 import xreadlines
1379 for line in xreadlines.xreadlines(file):
1380 ...do something to line...
1381
1382 This is equivalent to the previous the speed record holder using
1383 file.readlines(sizehint). Note that if file is a real file object
1384 (as opposed to a file-like object), this is equivalent:
1385
1386 for line in file.xreadlines():
1387 ...do something to line...
1388
Tim Peters36cdad12000-12-29 02:06:45 +00001389- The bisect module has new functions bisect_left, insort_left,
1390 bisect_right and insort_right. The old names bisect and insort
1391 are now aliases for bisect_right and insort_right. XXX_right
1392 and XXX_left methods differ in what happens when the new element
1393 compares equal to one or more elements already in the list: the
1394 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001395 right. Code that doesn't care where equal elements end up should
1396 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001397
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001398- The new curses.panel module wraps the panel library that forms part
1399 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1400
Guido van Rossumf61f1662001-01-10 20:13:55 +00001401- The SocketServer module now sets the allow_reuse_address flag by
1402 default in the TCPServer class.
1403
1404- A new function, sys._getframe(), returns the stack frame pointer of
1405 the caller. This is intended only as a building block for
1406 higher-level mechanisms such as string interpolation.
1407
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001408- The pyexpat module supports a number of new handlers, which are
1409 available only in expat 1.2. If invocation of a callback fails, it
1410 will report an additional frame in the traceback. Parser objects
1411 participate now in garbage collection. If expat reports an unknown
1412 encoding, pyexpat will try to use a Python codec; that works only
1413 for single-byte charsets. The parser type objects is exposed as
1414 XMLParserObject.
1415
1416- xml.dom now offers standard definitions for symbolic node type and
1417 exception code constants, and a hierarchy of DOM exceptions. minidom
1418 was adjusted to use them.
1419
1420- The conformance of xml.dom.minidom to the DOM specification was
1421 improved. It detects a number of additional error cases; the
1422 previous/next relationship works even when the tree is modified;
1423 Node supports the normalize() method; NamedNodeMap, DocumentType and
1424 DOMImplementation classes were added; Element supports the
1425 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1426 method.
1427
Guido van Rossumf61f1662001-01-10 20:13:55 +00001428Build issues
1429
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001430- For Unix (and Unix-compatible) builds, configuration and building of
1431 extension modules is now greatly automated. Rather than having to
1432 edit the Modules/Setup file to indicate which modules should be
1433 built and where their include files and libraries are, a
1434 distutils-based setup.py script now takes care of building most
1435 extension modules. All extension modules built this way are built
1436 as shared libraries. Only a few modules that must be linked
1437 statically are still listed in the Setup file; you won't need to
1438 edit their configuration.
1439
1440- Python should now build out of the box on Cygwin. If it doesn't,
1441 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001442
1443- Python now always uses its own (renamed) implementation of getopt()
1444 -- there's too much variation among C library getopt()
1445 implementations.
1446
1447- C++ compilers are better supported; the CXX macro is always set to a
1448 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001449
Tim Petersd92dfe02000-12-12 01:18:41 +00001450Windows changes
1451
1452- select module: By default under Windows, a select() call
1453 can specify no more than 64 sockets. Python now boosts
1454 this Microsoft default to 512. If you need even more than
1455 that, see the MS docs (you'll need to #define FD_SETSIZE
1456 and recompile Python from source).
1457
Guido van Rossumf61f1662001-01-10 20:13:55 +00001458- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1459 subdirectory is no more!
1460
Tim Petersa3a3a032000-11-30 05:22:44 +00001461
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001462What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001463=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001464
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001465Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001466changes are in the file HISTORY. If you are making the jump directly
1467from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1468HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001469
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001470Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1471the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1472http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001473
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001474--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001475
1476======================================================================
1477
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001478What's new in 2.0 (since release candidate 1)?
1479==============================================
1480
1481Standard library
1482
1483- The copy_reg module was modified to clarify its intended use: to
1484 register pickle support for extension types, not for classes.
1485 pickle() will raise a TypeError if it is passed a class.
1486
1487- Fixed a bug in gettext's "normalize and expand" code that prevented
1488 it from finding an existing .mo file.
1489
1490- Restored support for HTTP/0.9 servers in httplib.
1491
Tim Peters989b7b92000-10-16 20:24:53 +00001492- The math module was changed to stop raising OverflowError in case of
1493 underflow, and return 0 instead in underflow cases. Whether Python
1494 used to raise OverflowError in case of underflow was platform-
1495 dependent (it did when the platform math library set errno to ERANGE
1496 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001497
1498- Fixed a bug in StringIO that occurred when the file position was not
1499 at the end of the file and write() was called with enough data to
1500 extend past the end of the file.
1501
1502- Fixed a bug that caused Tkinter error messages to get lost on
1503 Windows. The bug was fixed by replacing direct use of
1504 interp->result with Tcl_GetStringResult(interp).
1505
1506- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1507 redirect response.
1508
1509- Several changes were made to distutils: Some debugging code was
1510 removed from util. Fixed the installer used when an external zip
1511 program (like WinZip) is not found; the source code for this
1512 installer is in Misc/distutils. check_lib() was modified to behave
1513 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1514 test for whether installed modules are on sys.path was changed to
1515 use both normcase() and normpath().
1516
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001517- Several minor bugs were fixed in the xml package (the minidom,
1518 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001519
1520- The regression test driver (regrtest.py) behavior when invoked with
1521 -l changed: It now reports a count of objects that are recognized as
1522 garbage but not freed by the garbage collector.
1523
Tim Peters989b7b92000-10-16 20:24:53 +00001524- The regression test for the math module was changed to test
1525 exceptional behavior when the test is run in verbose mode. Python
1526 cannot yet guarantee consistent exception behavior across platforms,
1527 so the exception part of test_math is run only in verbose mode, and
1528 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001529
1530Internals
1531
1532- PyOS_CheckStack() has been disabled on Win64, where it caused
1533 test_sre to fail.
1534
1535Build issues
1536
1537- Changed compiler flags, so that gcc is always invoked with -Wall and
1538 -Wstrict-prototypes. Users compiling Python with GCC should see
1539 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001540 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001541 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001542
Tim Petersa3a3a032000-11-30 05:22:44 +00001543- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001544
1545Tools and other miscellany
1546
1547- The compiler in Tools/compiler was updated to support the new
1548 language features introduced in 2.0: extended print statement, list
1549 comprehensions, and augmented assignments. The new compiler should
1550 also be backwards compatible with Python 1.5.2; the compiler will
1551 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001552 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001553
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001554What's new in 2.0 release candidate 1 (since beta 2)?
1555=====================================================
1556
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001557What is release candidate 1?
1558
1559We believe that release candidate 1 will fix all known bugs that we
1560intend to fix for the 2.0 final release. This release should be a bit
1561more stable than the previous betas. We would like to see even more
1562widespread testing before the final release, so we are producing this
1563release candidate. The final release will be exactly the same unless
1564any show-stopping (or brown bag) bugs are found by testers of the
1565release candidate.
1566
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001567All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001568to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001569
1570Core language, builtins, and interpreter
1571
1572- A bug that caused crashes when __coerce__ was used with augmented
1573 assignment, e.g. +=, was fixed.
1574
1575- Raise ZeroDivisionError when raising zero to a negative number,
1576 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1577 power operator and the result of math.pow(0.0, -2.0) will vary by
1578 platform. On Linux, it raises a ValueError.
1579
1580- A bug in Unicode string interpolation was fixed that occasionally
1581 caused errors with formats including "%%". For example, the
1582 following expression "%% %s" % u"abc" no longer raises a TypeError.
1583
1584- Compilation of deeply nested expressions raises MemoryError instead
1585 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1586
1587- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1588 rendering them useless. They are now written in binary mode again.
1589
1590Standard library
1591
1592- Keyword arguments are now accepted for most pattern and match object
1593 methods in SRE, the standard regular expression engine.
1594
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001595- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001596 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001597
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001598- Several bugs in the Unicode handling and error handling in _tkinter
1599 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001600
1601- Fix memory management errors in Merge() and Tkapp_Call() routines.
1602
1603- Several changes were made to cStringIO to make it compatible with
1604 the file-like object interface and with StringIO. If operations are
1605 performed on a closed object, an exception is raised. The truncate
1606 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001607 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001608
1609- There were many changes made to the linuxaudiodev module and its
1610 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001611 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001612
1613 Note that this module is named poorly, because it should work
1614 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001615 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001616
1617 The module now raises exceptions when errors occur instead of
1618 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1619 audio) and defines a getptr() method that calls the
1620 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1621
1622- The library_version attribute, introduced in an earlier beta, was
1623 removed because it can not be supported with early versions of the C
1624 readline library, which provides no way to determine the version at
1625 compile-time.
1626
1627- The binascii module is now enabled on Win64.
1628
Tim Peters46446d62000-10-09 21:19:31 +00001629- tokenize.py no longer suffers "recursion depth" errors when parsing
1630 programs with very long string literals.
1631
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001632Internals
1633
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001634- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001635 which is called when the interpreter starts up to determine where
1636 the standard library is installed. These vulnerabilities affect all
1637 previous versions of Python and can be exploited by setting very
1638 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1639 setuid Python script, although use of the wrapper in
1640 Misc/setuid-prog.c will eliminate the vulnerability.
1641
1642- Fixed garbage collection bugs in instance creation that were
1643 triggered when errors occurred during initialization. The solution,
1644 applied in cPickle and in PyInstance_New(), is to call
1645 PyObject_GC_Init() after the initialization of the object's
1646 container attributes is complete.
1647
1648- pyexpat adds definitions of PyModule_AddStringConstant and
1649 PyModule_AddObject if the Python version is less than 2.0, which
1650 provides compatibility with PyXML on Python 1.5.2.
1651
1652- If the platform has a bogus definition for LONG_BIT (the number of
1653 bits in a long), an error will be reported at compile time.
1654
1655- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1656 collection crashes and possibly other, unreported crashes.
1657
1658- Fixed a memory leak in _PyUnicode_Fini().
1659
1660Build issues
1661
1662- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001663 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001664 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001665
1666- The mmap.PAGESIZE constant is now initialized using sysconf when
1667 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1668
1669- The md5 file should now compile on all platforms.
1670
1671- The select module now compiles on platforms that do not define
1672 POLLRDNORM and related constants.
1673
1674- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001675 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001676
Jeremy Hylton10921202000-10-09 18:34:12 +00001677- BeOS: A number of changes were made to the build and installation
1678 process. ar-fake now operates on a directory of object files.
1679 dl_export.h is gone, and its macros now appear on the mwcc command
1680 line during build on PPC BeOS.
1681
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001682- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001683 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001684
1685- Cygwin: Support for shared libraries, Tkinter, and sockets.
1686
1687- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1688
1689Tools and other miscellany
1690
1691- Removed debugging prints from main used with freeze.
1692
Tim Peters46446d62000-10-09 21:19:31 +00001693- IDLE auto-indent no longer crashes when it encounters Unicode
1694 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001695
1696What's new in 2.0 beta 2 (since beta 1)?
1697========================================
1698
1699Core language, builtins, and interpreter
1700
Tim Peters482c0212000-09-26 06:33:09 +00001701- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001702 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001703
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001704- Add -h and -V command line options to print the usage message and
1705 Python version number and exit immediately.
1706
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001707- eval() and exec accept Unicode objects as code parameters.
1708
1709- getattr() and setattr() now also accept Unicode objects for the
1710 attribute name, which are converted to strings using the default
1711 encoding before lookup.
1712
1713- Multiplication on string and Unicode now does proper bounds
1714 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1715 string is too long."
1716
1717- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001718 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001719
Jeremy Hylton1b618592000-09-26 05:32:36 +00001720
1721Standard library and extensions
1722
Guido van Rossum5b08f132001-04-16 02:05:23 +00001723- socket module: the OpenSSL code now adds support for RAND_status()
1724 and EGD (Entropy Gathering Device).
1725
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001726- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001727 argument checking; it still takes no arguments.
1728
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001729- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001730
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001731- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001732
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001733- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001734
1735- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001736 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001737
1738- copy: Copy Unicode objects atomically.
1739
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001740- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001741
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001742- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001743
Fred Drake67233bc2000-09-26 16:40:27 +00001744- dbm: Add get() and setdefault() methods to dbm object. Add constant
1745 `library' to module that names the library used. Added doc strings
1746 and method names to error messages. Uses configure to determine
1747 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1748 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001749
1750- distutils: Update to version 0.9.3.
1751
1752- dl: Add several dl.RTLD_ constants.
1753
1754- fpectl: Now supported on FreeBSD.
1755
1756- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1757 found by the collector will be saved in gc.garbage. This is useful
1758 for debugging a program that creates reference cycles.
1759
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001760- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001761 of HTTP class. Do not close socket on zero-length response. Do not
1762 crash when server sends invalid content-length header.
1763
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001764- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001765
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001766- marshal: When reading a short, sign-extend on platforms where shorts
1767 are bigger than 16 bits. When reading a long, repair the unportable
1768 sign extension that was being done for 64-bit machines. (It assumed
1769 that signed right shift sign-extends.)
1770
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001771- operator: Add contains(), invert(), __invert__() as aliases for
1772 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001773
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001774- os: Add support for popen2() and popen3() on all platforms where
1775 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001776
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001777- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001778 clicking on a file in Explorer (or passing the file name to the
1779 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001780
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001781- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001782 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001783
1784- pickle: Now raises ValueError when an invalid pickle that contains
1785 a non-string repr where a string repr was expected. This behavior
1786 matches cPickle.
1787
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001788- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001789
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001790- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001791
1792- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001793 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001794 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001795
1796- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001797 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001798
1799- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001800 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001801 few cycles during startup since the first call to
1802 setdefaultencoding() will initialize the codec registry and the
1803 encodings package.
1804
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001805- socket: Support for size hint in readlines() method of object returned
1806 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001807
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001808- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001809 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001810 is followed by whitespace.
1811
Tim Petersa3a3a032000-11-30 05:22:44 +00001812- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001813
1814- struct: Check ranges for bytes and shorts.
1815
1816- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001817 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001818
1819- Tkinter: Image objects are now guaranteed to have unique ids. Set
1820 event.delta to zero if Tk version doesn't support mousewheel.
1821 Removed some debugging prints.
1822
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001823- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001824
Fred Drake67233bc2000-09-26 16:40:27 +00001825- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001826 which works around a bug in Norton AntiVirus 2000 that leads directly
1827 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001828
1829- xml: New version detection code allows PyXML to override standard
1830 XML package if PyXML version is greater than 0.6.1.
1831
Fred Drake64bb3802000-09-26 16:21:35 +00001832- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1833 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1834 tree only for nodes which are sufficiently interesting to a specific
1835 application. Does not provide the HTML-specific extensions. Still
1836 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001837
Fred Drake64bb3802000-09-26 16:21:35 +00001838- xml.sax: SAX 2 support for Python, including all the handler
1839 interfaces needed to process XML 1.0 compliant XML. Some
1840 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001841
Fred Drake64bb3802000-09-26 16:21:35 +00001842- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1843 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001844
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001845
Jeremy Hylton1b618592000-09-26 05:32:36 +00001846C API
1847
1848- Add three new convenience functions for module initialization --
1849 PyModule_AddObject(), PyModule_AddIntConstant(), and
1850 PyModule_AddStringConstant().
1851
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001852- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001853 removed and add #error to Python.h if NULL isn't defined after
1854 #include of stdio.h.
1855
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001856- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001857 backwards compatibility (at the source level) with old extensions.
1858
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001859- A wrapper API was added for signal() and sigaction(). Instead of
1860 either function, always use PyOS_getsig() to get a signal handler
1861 and PyOS_setsig() to set one. A new convenience typedef
1862 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001863
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001864- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001865 internal data buffer and size of a string object -- or the default
1866 encoded version of a Unicode object.
1867
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001868- PyString_Size() and PyString_AsString() accept Unicode objects.
1869
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001870- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001871 exists). INT_MAX and LONG_MAX will always be defined, even if
1872 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001873
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001874- PyFloat_FromString takes a second argument, pend, that was
1875 effectively useless. It is now officially useless but preserved for
1876 backwards compatibility. If the pend argument is not NULL, *pend is
1877 set to NULL.
1878
1879- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1880 for the attribute name. See note on getattr() above.
1881
1882- A few bug fixes to argument processing for Unicode.
1883 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1884 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1885 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001886 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001887
1888- Py_BuildValue accepts B format (for bgen-generated code).
1889
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001890
Jeremy Hylton1b618592000-09-26 05:32:36 +00001891Internals
1892
1893- On Unix, fix code for finding Python installation directory so that
1894 it works when argv[0] is a relative path.
1895
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001896- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001897 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001898 rather than by generating a copy of the object.
1899
Tim Peters482c0212000-09-26 06:33:09 +00001900- Several of the internal Unicode tables are much smaller now, and
1901 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001902
Jeremy Hylton97693b02000-09-26 17:42:51 +00001903- In the garbage collector: Fixed bug in collection of tuples. Fixed
1904 bug that caused some instances to be removed from the container set
1905 while they were still live. Fixed parsing in gc.set_debug() for
1906 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001907
1908- Fixed refcount problem in instance deallocation that only occurred
1909 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1910
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001911- On Windows, getpythonregpath is now protected against null data in
1912 registry key.
1913
1914- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001915 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001916
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001917
Jeremy Hylton1b618592000-09-26 05:32:36 +00001918Build and platform-specific issues
1919
1920- Better support of GNU Pth via --with-pth configure option.
1921
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001922- Python/C API now properly exposed to dynamically-loaded extension
1923 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001924
1925- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1926 Don't define MS_SYNC to be zero when it is undefined. Added missing
1927 prototypes in posixmodule.c.
1928
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001929- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001930 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001931
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001932- Fix largefile support on older NetBSD systems and OpenBSD by adding
1933 define for TELL64.
1934
1935
1936Tools and other miscellany
1937
1938- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1939
1940- freeze: The modulefinder now works with 2.0 opcodes.
1941
Tim Petersa3a3a032000-11-30 05:22:44 +00001942- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001943 Move hackery of sys.argv until after the Tk instance has been
1944 created, which allows the application-specific Tkinter
1945 initialization to be executed if present; also pass an explicit
1946 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001947
Jeremy Hylton1b618592000-09-26 05:32:36 +00001948
1949What's new in 2.0 beta 1?
1950=========================
1951
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001952Source Incompatibilities
1953------------------------
1954
1955None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1956such as single-argument append(), connect() and bind(), and changes to
1957str(long) and repr(float).
1958
1959
1960Binary Incompatibilities
1961------------------------
1962
1963- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1964with Python 2.0; these extensions will have to be rebuilt for Python
19652.0.
1966
1967- On Windows, attempting to import a third party extension built for
1968Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1969can do about this. Check your PYTHONPATH environment variable!
1970
1971- Python bytecode files (*.pyc and *.pyo) are not compatible between
1972releases.
1973
1974
1975Overview of Changes Since 1.6
1976-----------------------------
1977
1978There are many new modules (including brand new XML support through
1979the xml package, and i18n support through the gettext module); a list
1980of all new modules is included below. Lots of bugs have been fixed.
1981
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001982The process for making major new changes to the language has changed
1983since Python 1.6. Enhancements must now be documented by a Python
1984Enhancement Proposal (PEP) before they can be accepted.
1985
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001986There are several important syntax enhancements, described in more
1987detail below:
1988
1989 - Augmented assignment, e.g. x += 1
1990
1991 - List comprehensions, e.g. [x**2 for x in range(10)]
1992
1993 - Extended import statement, e.g. import Module as Name
1994
1995 - Extended print statement, e.g. print >> file, "Hello"
1996
1997Other important changes:
1998
1999 - Optional collection of cyclical garbage
2000
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002001Python Enhancement Proposal (PEP)
2002---------------------------------
2003
2004PEP stands for Python Enhancement Proposal. A PEP is a design
2005document providing information to the Python community, or describing
2006a new feature for Python. The PEP should provide a concise technical
2007specification of the feature and a rationale for the feature.
2008
2009We intend PEPs to be the primary mechanisms for proposing new
2010features, for collecting community input on an issue, and for
2011documenting the design decisions that have gone into Python. The PEP
2012author is responsible for building consensus within the community and
2013documenting dissenting opinions.
2014
2015The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002016
2017Augmented Assignment
2018--------------------
2019
2020This must have been the most-requested feature of the past years!
2021Eleven new assignment operators were added:
2022
Guido van Rossume905e952000-09-05 12:42:46 +00002023 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002024
2025For example,
2026
2027 A += B
2028
2029is similar to
2030
2031 A = A + B
2032
2033except that A is evaluated only once (relevant when A is something
2034like dict[index].attr).
2035
2036However, if A is a mutable object, A may be modified in place. Thus,
2037if A is a number or a string, A += B has the same effect as A = A+B
2038(except A is only evaluated once); but if a is a list, A += B has the
2039same effect as A.extend(B)!
2040
2041Classes and built-in object types can override the new operators in
2042order to implement the in-place behavior; the not-in-place behavior is
2043used automatically as a fallback when an object doesn't implement the
2044in-place behavior. For classes, the method name is derived from the
2045method name for the corresponding not-in-place operator by inserting
2046an 'i' in front of the name, e.g. __iadd__ implements in-place
2047__add__.
2048
2049Augmented assignment was implemented by Thomas Wouters.
2050
2051
2052List Comprehensions
2053-------------------
2054
2055This is a flexible new notation for lists whose elements are computed
2056from another list (or lists). The simplest form is:
2057
2058 [<expression> for <variable> in <sequence>]
2059
Guido van Rossum56db0952000-09-06 23:34:25 +00002060For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002061This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002062
2063You can also add a condition:
2064
2065 [<expression> for <variable> in <sequence> if <condition>]
2066
2067For example, [w for w in words if w == w.lower()] would yield the list
2068of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002069than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002070
2071You can also have nested for loops and more than one 'if' clause. For
2072example, here's a function that flattens a sequence of sequences::
2073
2074 def flatten(seq):
2075 return [x for subseq in seq for x in subseq]
2076
2077 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2078
2079This prints
2080
2081 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2082
2083List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002084Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002085
2086
2087Extended Import Statement
2088-------------------------
2089
2090Many people have asked for a way to import a module under a different
2091name. This can be accomplished like this:
2092
2093 import foo
2094 bar = foo
2095 del foo
2096
2097but this common idiom gets old quickly. A simple extension of the
2098import statement now allows this to be written as follows:
2099
2100 import foo as bar
2101
2102There's also a variant for 'from ... import':
2103
2104 from foo import bar as spam
2105
2106This also works with packages; e.g. you can write this:
2107
2108 import test.regrtest as regrtest
2109
2110Note that 'as' is not a new keyword -- it is recognized only in this
2111context (this is only possible because the syntax for the import
2112statement doesn't involve expressions).
2113
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002114Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002115
2116
2117Extended Print Statement
2118------------------------
2119
2120Easily the most controversial new feature, this extension to the print
2121statement adds an option to make the output go to a different file
2122than the default sys.stdout.
2123
2124For example, to write an error message to sys.stderr, you can now
2125write:
2126
2127 print >> sys.stderr, "Error: bad dog!"
2128
2129As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002130evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002131
2132 print >> None, "Hello world"
2133
2134is equivalent to
2135
2136 print "Hello world"
2137
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002138Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002139
2140
2141Optional Collection of Cyclical Garbage
2142---------------------------------------
2143
2144Python is now equipped with a garbage collector that can hunt down
2145cyclical references between Python objects. It's no replacement for
2146reference counting; in fact, it depends on the reference counts being
2147correct, and decides that a set of objects belong to a cycle if all
2148their reference counts can be accounted for from their references to
2149each other. This devious scheme was first proposed by Eric Tiedemann,
2150and brought to implementation by Neil Schemenauer.
2151
2152There's a module "gc" that lets you control some parameters of the
2153garbage collection. There's also an option to the configure script
2154that lets you enable or disable the garbage collection. In 2.0b1,
2155it's on by default, so that we (hopefully) can collect decent user
2156experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002157performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002158off by default in the final 2.0 release.
2159
2160
2161Smaller Changes
2162---------------
2163
2164A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2165map(None, seq1, seq2, ...) when the sequences have the same length;
2166i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2167the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002168zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002169
2170sys.version_info is a tuple (major, minor, micro, level, serial).
2171
2172Dictionaries have an odd new method, setdefault(key, default).
2173dict.setdefault(key, default) returns dict[key] if it exists; if not,
2174it sets dict[key] to default and returns that value. Thus:
2175
2176 dict.setdefault(key, []).append(item)
2177
2178does the same work as this common idiom:
2179
2180 if not dict.has_key(key):
2181 dict[key] = []
2182 dict[key].append(item)
2183
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002184There are two new variants of SyntaxError that are raised for
2185indentation-related errors: IndentationError and TabError.
2186
2187Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2188escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002189
2190The limits on the size of expressions and file in Python source code
2191have been raised from 2**16 to 2**32. Previous versions of Python
2192were limited because the maximum argument size the Python VM accepted
2193was 2**16. This limited the size of object constructor expressions,
2194e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2195limit was raised thanks to a patch by Charles Waldman that effectively
2196fixes the problem. It is now much more likely that you will be
2197limited by available memory than by an arbitrary limit in Python.
2198
2199The interpreter's maximum recursion depth can be modified by Python
2200programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2201limit is the maximum number of recursive calls that can be made by
2202Python code. The limit exists to prevent infinite recursion from
2203overflowing the C stack and causing a core dump. The default value is
22041000. The maximum safe value for a particular platform can be found
2205by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002206
2207New Modules and Packages
2208------------------------
2209
2210atexit - for registering functions to be called when Python exits.
2211
2212imputil - Greg Stein's alternative API for writing custom import
2213hooks.
2214
2215pyexpat - an interface to the Expat XML parser, contributed by Paul
2216Prescod.
2217
2218xml - a new package with XML support code organized (so far) in three
2219subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2220would fill a volume. There's a special feature whereby a
2221user-installed package named _xmlplus overrides the standard
2222xmlpackage; this is intended to give the XML SIG a hook to distribute
2223backwards-compatible updates to the standard xml package.
2224
2225webbrowser - a platform-independent API to launch a web browser.
2226
2227
Guido van Rossume905e952000-09-05 12:42:46 +00002228Changed Modules
2229---------------
2230
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002231array -- new methods for array objects: count, extend, index, pop, and
2232remove
2233
2234binascii -- new functions b2a_hex and a2b_hex that convert between
2235binary data and its hex representation
2236
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002237calendar -- Many new functions that support features including control
2238over which day of the week is the first day, returning strings instead
2239of printing them. Also new symbolic constants for days of week,
2240e.g. MONDAY, ..., SUNDAY.
2241
2242cgi -- FieldStorage objects have a getvalue method that works like a
2243dictionary's get method and returns the value attribute of the object.
2244
2245ConfigParser -- The parser object has new methods has_option,
2246remove_section, remove_option, set, and write. They allow the module
2247to be used for writing config files as well as reading them.
2248
2249ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002250optionally support the RFC 959 REST command.
2251
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002252gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002253
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002254httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2255the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002256
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002257locale -- implement getdefaultlocale for Win32 and Macintosh
2258
2259marshal -- no longer dumps core when marshaling deeply nested or
2260recursive data structures
2261
2262os -- new functions isatty, seteuid, setegid, setreuid, setregid
2263
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002264os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2265support under Unix.
2266
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002267os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002268
2269os.path -- fix semantics of os.path.commonprefix
2270
2271smtplib -- support for sending very long messages
2272
2273socket -- new function getfqdn()
2274
2275readline -- new functions to read, write and truncate history files.
2276The readline section of the library reference manual contains an
2277example.
2278
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002279select -- add interface to poll system call
2280
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002281shutil -- new copyfileobj function
2282
2283SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2284HTTP server.
2285
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002286Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002287
2288urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002289e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002290
2291whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002292
2293
2294Obsolete Modules
2295----------------
2296
2297None. However note that 1.6 made a whole slew of modules obsolete:
2298stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2299poly, zmod, strop, util, whatsound.
2300
2301
2302Changed, New, Obsolete Tools
2303----------------------------
2304
Tim Peters8b092332000-09-05 20:15:25 +00002305None.
Guido van Rossume905e952000-09-05 12:42:46 +00002306
2307
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002308C-level Changes
2309---------------
2310
2311Several cleanup jobs were carried out throughout the source code.
2312
2313All C code was converted to ANSI C; we got rid of all uses of the
2314Py_PROTO() macro, which makes the header files a lot more readable.
2315
2316Most of the portability hacks were moved to a new header file,
2317pyport.h; several other new header files were added and some old
2318header files were removed, in an attempt to create a more rational set
2319of header files. (Few of these ever need to be included explicitly;
2320they are all included by Python.h.)
2321
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002322Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002323and Win64, especially for the new Intel Itanium processor. Mick also
2324added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002325
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002326The C APIs to return an object's size have been update to consistently
2327use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2328previous versions, the abstract interfaces used PyXXX_Length and the
2329concrete interfaces used PyXXX_Size. The old names,
2330e.g. PyObject_Length, are still available for backwards compatibility
2331at the API level, but are deprecated.
2332
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002333The PyOS_CheckStack function has been implemented on Windows by
2334Fredrik Lundh. It prevents Python from failing with a stack overflow
2335on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002336
2337The GC changes resulted in creation of two new slots on object,
2338tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002339the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002340
2341The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002342C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002343
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002344PyErr_Format has been updated to automatically calculate the size of
2345the buffer needed to hold the formatted result string. This change
2346prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002347
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002348New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002349
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002350PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2351that are the same as their non-Ex counterparts except they take an
2352extra flag argument that tells them to close the file when done.
2353
2354XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002355
Tim Peters8b092332000-09-05 20:15:25 +00002356
2357Windows Changes
2358---------------
2359
2360New popen2/popen3/peopen4 in os module (see Changed Modules above).
2361
2362os.popen is much more usable on Windows 95 and 98. See Microsoft
2363Knowledge Base article Q150956. The Win9x workaround described there
2364is implemented by the new w9xpopen.exe helper in the root of your
2365Python installation. Note that Python uses this internally; it is not
2366a standalone program.
2367
2368Administrator privileges are no longer required to install Python
2369on Windows NT or Windows 2000. If you have administrator privileges,
2370Python's registry info will be written under HKEY_LOCAL_MACHINE.
2371Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002372under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002373uses of Python, but will prevent some advanced uses from working
2374(for example, running a Python script as an NT service, or possibly
2375from CGI).
2376
2377[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2378installer; instead, it installs the needed Tcl/Tk files directly in the
2379Python directory. If you already have a Tcl/Tk installation, this
2380wastes some disk space (about 4 Megs) but avoids problems with
2381conflicting Tcl/Tk installations, and makes it much easier for Python
2382to ensure that Tcl/Tk can find all its files.
2383
2384[This was new in 1.6] The Windows installer now installs by default in
2385\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2386
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002387
2388Updates to the changes between 1.5.2 and 1.6
2389--------------------------------------------
2390
2391The 1.6 NEWS file can't be changed after the release is done, so here
2392is some late-breaking news:
2393
2394New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2395and changes to getlocale() and setlocale().
2396
2397The new module is now enabled per default.
2398
2399It is not true that the encodings codecs cannot be used for normal
2400strings: the string.encode() (which is also present on 8-bit strings
2401!) allows using them for 8-bit strings too, e.g. to convert files from
2402cp1252 (Windows) to latin-1 or vice-versa.
2403
2404Japanese codecs are available from Tamito KAJIYAMA:
2405http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2406
2407
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002408======================================================================