blob: 93555e6fada7761523a0259c27aae2c85507952a [file] [log] [blame]
Tim Petersb07352e2001-09-08 01:25:47 +00001What's New in Python 2.2a4?
2===========================
3
4Core
5
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00006- PyUnicode_FromEncodedObject() now works very much like
7 PyObject_Str(obj) in that it tries to use __str__/tp_str
8 on the object if the object is not a string or buffer. This
9 makes unicode() behave like str() when applied to non-string/buffer
10 objects.
11
Martin v. Löwis2777c022001-09-19 13:47:32 +000012- PyFile_WriteObject now passes Unicode object to the file's write
13 method. As a result, all file-like object which may be the target
14 of a print statement must support Unicode objects, i.e. they must
15 at least convert them into ASCII strings.
16
Tim Peters59c9a642001-09-13 05:38:56 +000017- The builtin file type can be subclassed now. In the usual pattern,
18 "file" is the name of the builtin type, and file() is a new builtin
19 constructor, with the same signature as the builtin open() function.
20 file() is now the preferred way to open a file.
21
Guido van Rossum624c8af2001-09-18 15:21:04 +000022- In 2.2a3, __new__ would only see sequential arguments passed to the
23 type in a constructor call; __init__ would see both sequential and
24 positional arguments. This made no sense whatsoever any more, so
25 now both __new__ and __init__ see all arguments.
26
Tim Peters1f47d112001-09-12 23:40:29 +000027- In 2.2a3, hash() applied to an instance of a subclass of str or unicode
28 always returned 0. This has been repaired.
29
30- In 2.2a3, an operation on an instance of a subclass of an immutable type
31 (int, long, float, complex, tuple, str, unicode), where the subtype
32 didn't override the operation (and so the operation was handled by the
33 builtin type), could return that instance instead a value of the base
34 type. For example, if s was of a str sublass type, s[:] returned s
35 as-is. Now it returns a str with the same value as s.
36
Guido van Rossum624c8af2001-09-18 15:21:04 +000037- Applications using Jim Fulton's ExtensionClass module can now safely
38 be used with Python 2.2. In particular, Zope 2.4.1 now works with
39 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
40 examples also work again.
41
42- Thread scheduling on Solaris should be improved; it is no longer
43 necessary to insert a small sleep at the start of a thread in order
44 to let other runnable threads be scheduled.
45
Tim Petersb07352e2001-09-08 01:25:47 +000046Library
47
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +000048- The codecs module has grown four new helper APIs to access
49 builtin codecs: getencoder(), getdecoder(), getreader(),
50 getwriter().
51
Guido van Rossum624c8af2001-09-18 15:21:04 +000052- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
53 simplifies writing XML RPC servers.
54
55- os.path.realpath(): a new function that returns the absoute pathname
56 after interpretation of symbolic links. On non-Unix systems, this
57 is an alias for os.path.abspath().
58
Tim Peters16a77ad2001-09-08 04:00:12 +000059- operator.indexOf() (PySequence_Index() in the C API) now works with any
60 iterable object.
61
Guido van Rossum624c8af2001-09-18 15:21:04 +000062- smtplib now supports various authentication and security features of
63 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +000064
Guido van Rossum624c8af2001-09-18 15:21:04 +000065- hmac: a new module implementing keyed hashing for message
66 authentication.
67
68- mimetypes now recognizes more extensions and file types. At the
69 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +000070
Guido van Rossum624c8af2001-09-18 15:21:04 +000071- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +000072 Python 2.2 bytecode generation. It has also been promoted from a
73 Tool to a standard library package. (Tools/compiler still exists as
74 a sample driver.)
75
76- pydoc and inspect are now aware of new-style classes;
77 e.g. help(list) at the interactive prompt now shows proper
78 documentation for all operations on list objects.
79
80Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +000081
Tim Petersb07352e2001-09-08 01:25:47 +000082Build
83
Guido van Rossum624c8af2001-09-18 15:21:04 +000084- Large file support (LFS) is now automatic when the platform supports
85 it; no more manual configuration tweaks are needed. On Linux, at
86 least, it's possible to have a system whose C library supports large
87 files but whose kernel doesn't; in this case, large file support is
88 still enabled but doesn't do you any good unless you upgrade your
89 kernel or share your Python executable with another system whose
90 kernel has large file support.
91
92- The configure script now supplies plausible defaults in a
93 cross-compilation environment. This doesn't mean that the supplied
94 values are always correct, or that cross-compilation now works
95 flawlessly -- but it's a first step (and it shuts up most of
96 autoconf's warnings about AC_TRY_RUN).
97
98- The Unix build is now a bit less chatty, courtesy of the parser
99 generator. The build is completely silent (except for errors) when
100 using "make -s", thanks to a -q option to setup.py.
101
Tim Petersb07352e2001-09-08 01:25:47 +0000102C API
103
Guido van Rossum624c8af2001-09-18 15:21:04 +0000104- The "structmember" API now supports some new flag bits to deny read
105 and/or write access to attributes in restricted execution mode.
106
Tim Petersb07352e2001-09-08 01:25:47 +0000107New platforms
108
Guido van Rossum624c8af2001-09-18 15:21:04 +0000109- Compaq's iPAQ handheld, running the "familiar" Linux distribution
110 (http://familiar.handhelds.org).
111
Tim Petersb07352e2001-09-08 01:25:47 +0000112Tests
113
114Windows
115
Guido van Rossum624c8af2001-09-18 15:21:04 +0000116- Large file support now also works for files > 4GB, on filesystems
117 that support it (NTFS under Windows 2000).
118
Tim Petersb07352e2001-09-08 01:25:47 +0000119
Tim Petersedc99312001-08-22 21:36:50 +0000120What's New in Python 2.2a3?
121===========================
122
123Core
124
Tim Peters9fffa3e2001-09-04 05:14:19 +0000125- Conversion of long to float now raises OverflowError if the long is too
126 big to represent as a C double.
127
Tim Peters32f453e2001-09-03 08:35:41 +0000128- The 3-argument builtin pow() no longer allows a third non-None argument
129 if either of the first two arguments is a float, or if both are of
130 integer types and the second argument is negative (in which latter case
131 the arguments are converted to float, so this is really the same
132 restriction).
133
Tim Peters5d2b77c2001-09-03 05:47:38 +0000134- The builtin dir() now returns more information, and sometimes much
135 more, generally naming all attributes of an object, and all attributes
136 reachable from the object via its class, and from its class's base
137 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
138 an empty list. In 2.2a3,
139
140 >>> dir([])
141 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
142 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
143 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
144 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
145 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
146 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
147 'reverse', 'sort']
148
149 dir(module) continues to return only the module's attributes, though.
150
Tim Petersbdee63f2001-09-02 03:40:59 +0000151- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000152 than raising OverflowError. This is a partial implementation of PEP
153 237. You can use -Wdefault::OverflowWarning to enable a warning for
154 this situation, and -Werror::OverflowWarning to revert to the old
155 OverflowError exception.
156
Guido van Rossum61c345f2001-09-04 03:26:15 +0000157- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000158 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000159 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
160 -Qold, meaning the / operator has its classic meaning and no
161 warnings are issued. Using -Qwarn issues a run-time warning about
162 all uses of classic division for int and long arguments; -Qwarnall
163 also warns about classic division for float and complex arguments
164 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
165 new division by default, but only in the __main__ module. You can
166 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
167 __main__ module new division, and warns about classic division
168 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000169
Tim Petersbdee63f2001-09-02 03:40:59 +0000170- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000171 long, float, str, unicode, and tuple. (The types complex, list and
172 dictionary can also be subclassed; this was introduced earlier.)
173 Note that restrictions apply when subclassing immutable built-in
174 types: you can only affect the value of the instance by overloading
175 __new__. You can add mutable attributes, and the subclass instances
176 will have a __dict__ attribute, but you cannot change the "value"
177 (as implemented by the base class) of an immutable subclass instance
178 once it is created.
179
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000180- The dictionary constructor now takes an optional argument, a
181 mapping-like object, and initializes the dictionary from its
182 (key, value) pairs.
183
Tim Petersbdee63f2001-09-02 03:40:59 +0000184- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000185 "cooperative super calls" in a multiple inheritance setting. For an
186 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
187
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000188- A new built-in type, property, has been added. This enables the
189 creation of "properties". These are attributes implemented by
190 getter and setter functions (or only one of these for read-only or
191 write-only attributes), without the need to override __getattr__.
192 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000193
Tim Petersbdee63f2001-09-02 03:40:59 +0000194- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000195 liberalized, to allow leading zeroes. Examples of literals now
196 legal that were SyntaxErrors before:
197
198 00.0 0e3 0100j 07.5 00000000000000000008.
199
Tim Petersbdee63f2001-09-02 03:40:59 +0000200- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000201 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
202
Tim Petersedc99312001-08-22 21:36:50 +0000203Library
204
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000205- telnetlib includes symbolic names for the options, and support for
206 setting an option negotiation callback.
207
Tim Petersa40c7932001-09-05 22:36:56 +0000208- The new C standard no longer requires that math libraries set errno to
209 ERANGE on overflow. For platform libraries that exploit this new
210 freedom, Python's overflow-checking was wholly broken. A new overflow-
211 checking scheme attempts to repair that, but may not be reliable on all
212 platforms (C doesn't seem to provide anything both useful and portable
213 in this area anymore).
214
Martin v. Löwis44f86962001-09-05 13:44:54 +0000215- Asynchronous timeout actions are available through the new class
216 threading.Timer.
217
Tim Peters78526162001-09-05 00:53:45 +0000218- math.log and math.log10 now return sensible results for even huge
219 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
220
Tim Petersbdee63f2001-09-02 03:40:59 +0000221- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000222 currently held. See the docs for the imp module.
223
Tim Petersbdee63f2001-09-02 03:40:59 +0000224- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000225 dumps containing ints written on platforms where Python ints are 8 bytes.
226 When read on a box where Python ints are 4 bytes, such values are
227 converted to Python longs.
228
Tim Petersbdee63f2001-09-02 03:40:59 +0000229- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000230 code objects is no longer allowed. This plugs a security hole.
231
Steve Purcell6091cd62001-09-06 16:05:17 +0000232- unittest.TestResult instances no longer store references to tracebacks
233 generated by test failures. This prevents unexpected dangling references
234 to objects that should be garbage collected between tests.
235
Tim Petersedc99312001-08-22 21:36:50 +0000236Tools
237
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000238- Tools/scripts/fixdiv.py has been added which can be used to fix
239 division operators as per PEP 238.
240
Tim Petersedc99312001-08-22 21:36:50 +0000241Build
242
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000243- If you are an adventurous person using Mac OS X you may want to look at
244 Mac/OSX. There is a Makefile there that will build Python as a real Mac
245 application, which can be used for experimenting with Carbon or Cocoa.
246 Discussion of this on pythonmac-sig, please.
247
Tim Peters7eea37e2001-09-04 22:08:56 +0000248C API
249
250- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000251
Tim Peters9fffa3e2001-09-04 05:14:19 +0000252- Note that PyLong_AsDouble can fail! This has always been true, but no
253 callers checked for it. It's more likely to fail now, because overflow
254 errors are properly detected now. The proper way to check:
255
256 double x = PyLong_AsDouble(some_long_object);
257 if (x == -1.0 && PyErr_Occurred()) {
258 /* The conversion failed. */
259 }
260
Tim Petersbdee63f2001-09-02 03:40:59 +0000261- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000262 compile but will not participate in GC. To upgrade an extension
263 module:
264
265 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000266
Neil Schemenauer4042c692001-08-30 15:38:01 +0000267 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
268 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000269
Neil Schemenauer4042c692001-08-30 15:38:01 +0000270 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
271 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000272
Neil Schemenauer4042c692001-08-30 15:38:01 +0000273 - remove PyGC_HEAD_SIZE from object size calculations
274
275 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
276
Tim Petersbdee63f2001-09-02 03:40:59 +0000277- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000278 These can be used safely to construct string objects from a
279 sprintf-style format string (similar to the format string supported
280 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000281
Tim Petersedc99312001-08-22 21:36:50 +0000282New platforms
283
Tim Petersb7da0902001-09-02 23:01:43 +0000284- Stephen Hansen contributed patches sufficient to get a clean compile
285 under Borland C (Windows), but he reports problems running it and ran
286 out of time to complete the port. Volunteers? Expect a MemoryError
287 when importing the types module; this is probably shallow, and
288 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000289
Tim Petersedc99312001-08-22 21:36:50 +0000290Tests
291
292Windows
293
Tim Peters6e13a562001-09-06 00:32:15 +0000294- Large file support is now enabled on Win32 platforms as well as on
295 Win64. This means that, for example, you can use f.tell() and f.seek()
296 to manipulate files larger than 2 gigabytes (provided you have enough
297 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000298 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
299 filesize limit, and large file support makes no difference there.
300 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
301 NTFS has no practical limit on file size, and files of any size can be
302 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000303
Tim Petersbdee63f2001-09-02 03:40:59 +0000304- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000305 points to command.com (patch from Brian Quinlan).
306
Tim Petersedc99312001-08-22 21:36:50 +0000307
Tim Peters20f51a72001-07-21 02:31:40 +0000308What's New in Python 2.2a2?
309===========================
310
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000311Build
312
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000313- Tim Peters developed a brand new Windows installer using Wise 8.1,
314 generously donated to us by Wise Solutions.
315
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000316- configure supports a new option --enable-unicode, with the values
317 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
318 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000319
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000320- A new configure option --enable-framework builds a Mac OS X framework,
321 which "make frameworkinstall" will install. This provides a starting
322 point for more mac-like functionality, join pythonmac-sig@python.org
323 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000324
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000325- The NeXT platform is no longer supported.
326
327- The `new' module is now statically linked.
328
Tim Peters0afb6092001-08-15 06:06:44 +0000329Tools
330
331- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000332 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000333 the module docstring for details.
334
Tim Peters20f51a72001-07-21 02:31:40 +0000335Tests
336
Tim Peters5e824c32001-08-12 22:25:01 +0000337- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000338 platforms, allowing to give clearer test result output. regrtest
339 also has optional --use/-u switch to run normally disabled tests
340 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000341
Tim Peters20f51a72001-07-21 02:31:40 +0000342- Several new tests in the standard test suite, with special thanks to
343 Nick Mathewson.
344
345Core
346
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000347- The floor division operator // has been added as outlined in PEP
348 238. The / operator still provides classic division (and will until
349 Python 3.0) unless "from __future__ import division" is included, in
350 which case the / operator will provide true division. The operator
351 module provides truediv() and floordiv() functions. Augmented
352 assignment variants are included, as are the equivalent overloadable
353 methods and C API methods. See the PEP for a full discussion:
354 <http://python.sf.net/peps/pep-0238.html>
355
Tim Peters6cd6a822001-08-17 22:11:27 +0000356- Future statements are now effective in simulated interactive shells
357 (like IDLE). This should "just work" by magic, but read Michael
358 Hudson's "Future statements in simulated shells" PEP 264 for full
359 details: <http://python.sf.net/peps/pep-0264.html>.
360
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000361- The type/class unification (PEP 252-253) was integrated into the
362 trunk and is not so tentative any more (the exact specification of
363 some features is still tentative). A lot of work has done on fixing
364 bugs and adding robustness and features (performance still has to
365 come a long way).
366
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000367- Warnings about a mismatch in the Python API during extension import
368 now use the Python warning framework (which makes it possible to
369 write filters for these warnings).
370
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000371- A function's __dict__ (aka func_dict) will now always be a
372 dictionary. It used to be possible to delete it or set it to None,
373 but now both actions raise TypeErrors. It is still legal to set it
374 to a dictionary object. Getting func.__dict__ before any attributes
375 have been assigned now returns an empty dictionary instead of None.
376
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000377- A new command line option, -E, was added which disables the use of
378 all environment variables, or at least those that are specifically
379 significant to Python. Usually those have a name starting with
380 "PYTHON". This was used to fix a problem where the tests fail if
381 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
382 older distribution.
383
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000384Library
385
Tim Peters5e824c32001-08-12 22:25:01 +0000386- New class Differ and new functions ndiff() and restore() in difflib.py.
387 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000388 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000389
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000390- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
391 value using the minimal quoting required for the value; more
392 reliable than using xml.sax.saxutils.escape() for attribute values.
393
394- Readline completion support for cmd.Cmd was added.
395
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000396- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
397
398- Added function threading.BoundedSemaphore()
399
400- Added Ka-Ping Yee's cgitb.py module.
401
402- The `new' module now exposes the CO_xxx flags.
403
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000404New platforms
405
406C API
407
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000408- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
409 which provide a cross-platform implementations for the
410 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
411 the standard sprintf() and vsprintf() C lib APIs, these versions
412 apply bounds checking on the used buffer which enhances protection
413 against buffer overruns.
414
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000415- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000416 and extensions using different Unicode widths is rendered next to
417 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000418 will result in an ImportError. Unicode extensions writers must make
419 sure to check the Unicode width compatibility in their extensions by
420 using at least one of the mangled Unicode APIs in the extension.
421
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000422- Two new flags METH_NOARGS and METH_O are available in method definition
423 tables to simplify implementation of methods with no arguments and a
424 single untyped argument. Calling such methods is more efficient than
425 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
426 deprecated.
427
Tim Petersc1731372001-08-04 08:12:36 +0000428Windows
429
430- "import module" now compiles module.pyw if it exists and nothing else
431 relevant is found.
432
Tim Peters20f51a72001-07-21 02:31:40 +0000433
Guido van Rossum55a78992001-07-17 17:22:32 +0000434What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000435===========================
436
437Core
Tim Petersa814db52001-05-14 07:05:58 +0000438
Tim Peters6d6c1a32001-08-02 04:15:00 +0000439- TENTATIVELY, a large amount of code implementing much of what's
440 described in PEP 252 (Making Types Look More Like Classes) and PEP
441 253 (Subtyping Built-in Types) was added. This will be released
442 with Python 2.2a1. Documentation will be provided separately
443 through http://www.python.org/2.2/. The purpose of releasing this
444 with Python 2.2a1 is to test backwards compatibility. It is
445 possible, though not likely, that a decision is made not to release
446 this code as part of 2.2 final, if any serious backwards
447 incompapatibilities are found during alpha testing that cannot be
448 repaired.
449
Guido van Rossum55a78992001-07-17 17:22:32 +0000450- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000451 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000452 more 'yield' statements. See PEP 255. Since this adds a new
453 keyword to the language, this feature must be enabled by including a
454 future statement: "from __future__ import generators" (see PEP 236).
455 Generators will become a standard feature in a future release
456 (probably 2.3). Without this future statement, 'yield' remains an
457 ordinary identifier, but a warning is issued each time it is used.
458 (These warnings currently don't conform to the warnings framework of
459 PEP 230; we intend to fix this in 2.2a2.)
460
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000461- The UTF-16 codec was modified to be more RFC compliant. It will now
462 only remove BOM characters at the start of the string and then
463 only if running in native mode (UTF-16-LE and -BE won't remove a
464 leading BMO character).
465
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000466- Strings now have a new method .decode() to complement the already
467 existing .encode() method. These two methods provide direct access
468 to the corresponding decoders and encoders of the registered codecs.
469
470 To enhance the usability of the .encode() method, the special
471 casing of Unicode object return values was dropped (Unicode objects
472 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000473
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000474 Both methods will now return whatever the codec in charge of the
475 requested encoding returns as object, e.g. Unicode codecs will
476 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
477 will return u"äöü"). This enables codec writer to create codecs
478 for various simple to use conversions.
479
480 New codecs were added to demonstrate these new features (the .encode()
481 and .decode() columns indicate the type of the returned objects):
482
483 Name | .encode() | .decode() | Description
484 ----------------------------------------------------------------------
485 uu | string | string | UU codec (e.g. for email)
486 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000487 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000488 zlib | string | string | zlib compression
489 hex | string | string | 2-byte hex codec
490 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
491
Mark Hammond2a0af792001-05-14 03:09:36 +0000492- Some operating systems now support the concept of a default Unicode
493 encoding for file system operations. Notably, Windows supports 'mbcs'
494 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000495 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000496 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000497
498 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000499 functions that return filenames (such as os.listdir()) to return Python
500 string objects pre-encoded using the default file system encoding for
501 the platform. As this encoding is likely to be different from Python's
502 default encoding, converting this name to a Unicode object before passing
503 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000504 would attempt to use its default encoding (generally ASCII) rather than
505 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000506
Tim Petersa814db52001-05-14 07:05:58 +0000507 In general, this change simply removes surprises when working with
508 Unicode and the file system, making these operations work as you expect,
509 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000510 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000511
Tim Peters61dff2b2001-05-08 15:43:37 +0000512- Float (and complex) literals in source code were evaluated to full
513 precision only when running from a .py file; the same code loaded from a
514 .pyc (or .pyo) file could suffer numeric differences starting at about the
515 12th significant decimal digit. For example, on a machine with IEEE-754
516 floating arithmetic,
517
518 x = 9007199254740992.0
519 print long(x)
520
521 printed 9007199254740992 if run directly from .py, but 9007199254740000
522 if from a compiled (.pyc or .pyo) file. This was due to marshal using
523 str(float) instead of repr(float) when building code objects. marshal
524 now uses repr(float) instead, which should reproduce floats to full
525 machine precision (assuming the platform C float<->string I/O conversion
526 functions are of good quality).
527
528 This may cause floating-point results to change in some cases, and
529 usually for the better, but may also cause numerically unstable
530 algorithms to break.
531
Tim Peters2f228e72001-05-13 00:19:31 +0000532- The implementation of dicts suffers fewer collisions, which has speed
533 benefits. However, the order in which dict entries appear in dict.keys(),
534 dict.values() and dict.items() may differ from previous releases for a
535 given dict. Nothing is defined about this order, so no program should
536 rely on it. Nevertheless, it's easy to write test cases that rely on the
537 order by accident, typically because of printing the str() or repr() of a
538 dict to an "expected results" file. See Lib/test/test_support.py's new
539 sortdict(dict) function for a simple way to display a dict in sorted
540 order.
541
Tim Peters7a3bfc32001-06-12 01:22:22 +0000542- Many other small changes to dicts were made, resulting in faster
543 operation along the most common code paths.
544
Guido van Rossum10315822001-05-01 20:54:30 +0000545- Dictionary objects now support the "in" operator: "x in dict" means
546 the same as dict.has_key(x).
547
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000548- The update() method of dictionaries now accepts generic mapping
549 objects. Specifically the argument object must support the .keys()
550 and __getitem__() methods. This allows you to say, for example,
551 {}.update(UserDict())
552
Guido van Rossum10315822001-05-01 20:54:30 +0000553- Iterators were added; this is a generalized way of providing values
554 to a for loop. See PEP 234. There's a new built-in function iter()
555 to return an iterator. There's a new protocol to get the next value
556 from an iterator using the next() method (in Python) or the
557 tp_iternext slot (in C). There's a new protocol to get iterators
558 using the __iter__() method (in Python) or the tp_iter slot (in C).
559 Iterating (i.e. a for loop) over a dictionary generates its keys.
560 Iterating over a file generates its lines.
561
Tim Petersf553f892001-05-01 20:45:31 +0000562- The following functions were generalized to work nicely with iterator
563 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000564 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000565 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
566 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000567 join() method of strings
568 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000569 'x in y' and 'x not in y' (PySequence_Contains() in C API)
570 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000571 right-hand side of assignment statements with multiple targets, such as
572 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000573
Tim Petersd85e1022001-05-11 21:51:48 +0000574- Accessing module attributes is significantly faster (for example,
575 random.random or os.path or yourPythonModule.yourAttribute).
576
Tim Peterse63415e2001-05-08 04:38:29 +0000577- Comparing dictionary objects via == and != is faster, and now works even
578 if the keys and values don't support comparisons other than ==.
579
Tim Peters95bf9392001-05-10 08:32:44 +0000580- Comparing dictionaries in ways other than == and != is slower: there were
581 insecurities in the dict comparison implementation that could cause Python
582 to crash if the element comparison routines for the dict keys and/or
583 values mutated the dicts. Making the code bulletproof slowed it down.
584
Tim Peterseb28ef22001-06-02 05:27:19 +0000585- Collisions in dicts are resolved via a new approach, which can help
586 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000587 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000588 faster now. Thanks to Christian Tismer for pointing out the cause and
589 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000590
Tim Peters52e155e2001-06-16 05:42:57 +0000591- repr() is much faster for large containers (dict, list, tuple).
592
593
Tim Petersa814db52001-05-14 07:05:58 +0000594Library
595
Fred Drake960fdf92001-07-20 18:38:26 +0000596- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
597 were added to the string module. These a locale-indenpendent
598 constants, unlike letters, lowercase, and uppercase. These are now
599 use in appropriate locations in the standard library.
600
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000601- The flags used in dlopen calls can now be configured using
602 sys.setdlopenflags and queried using sys.getdlopenflags.
603
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000604- Fredrik Lundh's xmlrpclib is now a standard library module. This
605 provides full client-side XML-RPC support. In addition,
606 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
607 one asyncore-based). Thanks to Eric Raymond for the documentation.
608
Guido van Rossum643d3912001-07-05 14:46:25 +0000609- The xrange() object is simplified: it no longer supports slicing,
610 repetition, comparisons, efficient 'in' checking, the tolist()
611 method, or the start, stop and step attributes. See PEP 260.
612
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000613- A new function fnmatch.filter to filter lists of file names was added.
614
Barry Warsawffd674d2001-05-22 16:00:10 +0000615- calendar.py uses month and day names based on the current locale.
616
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000617- strop is now *really* obsolete (this was announced before with 1.6),
618 and issues DeprecationWarning when used (except for the four items
619 that are still imported into string.py).
620
Tim Petersa814db52001-05-14 07:05:58 +0000621- Cookie.py now sorts key+value pairs by key in output strings.
622
623- pprint.isrecursive(object) didn't correctly identify recursive objects.
624 Now it does.
625
Tim Peters95b3f782001-05-14 18:39:41 +0000626- pprint functions now much faster for large containers (tuple, list, dict).
627
Tim Peters7b9542a2001-06-10 23:40:19 +0000628- New 'q' and 'Q' format codes in the struct module, corresponding to C
629 types "long long" and "unsigned long long" (on Windows, __int64). In
630 native mode, these can be used only when the platform C compiler supports
631 these types (when HAVE_LONG_LONG is #define'd by the Python config
632 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000633 In standard mode, 'q' and 'Q' are supported on all platforms, and are
634 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000635
Guido van Rossum83213cc2001-06-12 16:48:52 +0000636- The site module installs a new built-in function 'help' that invokes
637 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
638 it displays a message reminding the user to use 'help()' or
639 'help(object)'.
640
Tim Petersa814db52001-05-14 07:05:58 +0000641Tests
642
643- New test_mutants.py runs dict comparisons where the key and value
644 comparison operators mutute the dicts randomly during comparison. This
645 rapidly causes Python to crash under earlier releases (not for the faint
646 of heart: it can also cause Win9x to freeze or reboot!).
647
648- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000649 pprint.isreadable() return sensible results. Also verifies that simple
650 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000651
Tim Peters4324aa32001-05-28 22:30:08 +0000652C API
653
654- Removed the unused last_is_sticky argument from the internal
655 _PyTuple_Resize(). If this affects you, you were cheating.
656
657
Guido van Rossum55a78992001-07-17 17:22:32 +0000658======================================================================
659
660
Guido van Rossumffe13be2001-04-16 18:46:45 +0000661What's New in Python 2.1 (final)?
662=================================
663
664We only changed a few things since the last release candidate, all in
665Python library code:
666
667- A bug in the locale module was fixed that affected locales which
668 define no grouping for numeric formatting.
669
670- A few bugs in the weakref module's implementations of weak
671 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
672 and the test suite was updated to check for these bugs.
673
674- An old bug in the os.path.walk() function (introduced in Python
675 2.0!) was fixed: a non-existent file would cause an exception
676 instead of being ignored.
677
678- Fixed a few bugs in the new symtable module found by Neil Norwitz's
679 PyChecker.
680
681
Guido van Rossum5b08f132001-04-16 02:05:23 +0000682What's New in Python 2.1c2?
683===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000684
Guido van Rossum5b08f132001-04-16 02:05:23 +0000685A flurry of small changes, and one showstopper fixed in the nick of
686time made it necessary to release another release candidate. The list
687here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000688
Guido van Rossum5b08f132001-04-16 02:05:23 +0000689Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000690
Guido van Rossum5b08f132001-04-16 02:05:23 +0000691- Tim discovered a nasty bug in the dictionary code, caused by
692 PyDict_Next() calling dict_resize(), and the GC code's use of
693 PyDict_Next() violating an assumption in dict_items(). This was
694 fixed with considerable amounts of band-aid, but the net effect is a
695 saner and more robust implementation.
696
697- Made a bunch of symbols static that were accidentally global.
698
699Build and Ports
700
701- The setup.py script didn't check for a new enough version of zlib
702 (1.1.3 is needed). Now it does.
703
704- Changed "make clean" target to also remove shared libraries.
705
706- Added a more general warning about the SGI Irix optimizer to README.
707
708Library
709
710- Fix a bug in urllib.basejoin("http://host", "../file.html") which
711 omitted the slash between host and file.html.
712
713- The mailbox module's _Mailbox class contained a completely broken
714 and undocumented seek() method. Ripped it out.
715
716- Fixed a bunch of typos in various library modules (urllib2, smtpd,
717 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
718
719- Fixed a few last-minute bugs in unittest.
720
721Extensions
722
723- Reverted the patch to the OpenSSL code in socketmodule.c to support
724 RAND_status() and the EGD, and the subsequent patch that tried to
725 fix it for pre-0.9.5 versions; the problem with the patch is that on
726 some systems it issues a warning whenever socket is imported, and
727 that's unacceptable.
728
729Tests
730
731- Fixed the pickle tests to work with "import test.test_pickle".
732
733- Tweaked test_locale.py to actually run the test Windows.
734
735- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
736 not "wb" (which is not a valid mode at all).
737
738- Fix pstats browser crashes. Import readline if it exists to make
739 the user interface nicer.
740
741- Add "import thread" to the top of test modules that import the
742 threading module (test_asynchat and test_threadedtempfile). This
743 prevents test failures caused by a broken threading module resulting
744 from a previously caught failed import.
745
746- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
747 needed on some platforms (e.g. Solaris 8) when the tests are run
748 twice in succession.
749
750- Skip rather than fail test_sunaudiodev if no audio device is found.
751
752
753What's New in Python 2.1c1?
754===========================
755
756This list was significantly updated when 2.1c2 was released; the 2.1c1
757release didn't mention most changes that were actually part of 2.1c1:
758
759Legal
760
761- Copyright was assigned to the Python Software Foundation (PSF) and a
762 PSF license (very similar to the CNRI license) was added.
763
764- The CNRI copyright notice was updated to include 2001.
765
766Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000767
Guido van Rossumc9932722001-04-12 02:31:27 +0000768- After a public outcry, assignment to __debug__ is no longer illegal;
769 instead, a warning is issued. It will become illegal in 2.2.
770
Guido van Rossum5b08f132001-04-16 02:05:23 +0000771- Fixed a core dump with "%#x" % 0, and changed the semantics so that
772 "%#x" now always prepends "0x", even if the value is zero.
773
774- Fixed some nits in the bytecode compiler.
775
776- Fixed core dumps when calling certain kinds of non-functions.
777
778- Fixed various core dumps caused by reference count bugs.
779
780Build and Ports
781
782- Use INSTALL_SCRIPT to install script files.
783
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000784- New port: SCO Unixware 7, by Billy G. Allie.
785
Guido van Rossum5b08f132001-04-16 02:05:23 +0000786- Updated RISCOS port.
787
788- Updated BeOS port and notes.
789
790- Various other porting problems resolved.
791
792Library
793
794- The TERMIOS and SOCKET modules are now truly obsolete and
795 unnecessary. Their symbols are incorporated in the termios and
796 socket modules.
797
798- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
799 better tests for pickling.
800
801- threading: make Condition.wait() robust against KeyboardInterrupt.
802
803- zipfile: add support to zipfile to support opening an archive
804 represented by an open file rather than a file name. Fix bug where
805 the archive was not properly closed. Fixed a bug in this bugfix
806 where flush() was called for a read-only file.
807
808- imputil: added an uninstall() method to the ImportManager.
809
810- Canvas: fixed bugs in lower() and tkraise() methods.
811
812- SocketServer: API change (added overridable close_request() method)
813 so that the TCP server can explicitly close the request.
814
815- pstats: Eric Raymond added a simple interactive statistics browser,
816 invoked when the module is run as a script.
817
818- locale: fixed a problem in format().
819
820- webbrowser: made it work when the BROWSER environment variable has a
821 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
822 KDE 2. Fixed some other nits.
823
824- unittest: changes to allow using a different exception than
825 AssertionError, and added a few more function aliases. Some other
826 small changes.
827
828- urllib, urllib2: fixed redirect problems and a coupleof other nits.
829
830- asynchat: fixed a critical bug in asynchat that slipped through the
831 2.1b2 release. Fixed another rare bug.
832
833- Fix some unqualified except: clauses (always a bad code example).
834
835XML
836
837- pyexpat: new API get_version_string().
838
839- Fixed some minidom bugs.
840
841Extensions
842
843- Fixed a core dump in _weakref. Removed the weakref.mapping()
844 function (it adds nothing to the API).
845
846- Rationalized the use of header files in the readline module, to make
847 it compile (albeit with some warnings) with the very recent readline
848 4.2, without breaking for earlier versions.
849
850- Hopefully fixed a buffering problem in linuxaudiodev.
851
852- Attempted a fix to make the OpenSSL support in the socket module
853 work again with pre-0.9.5 versions of OpenSSL.
854
855Tests
856
857- Added a test case for asynchat and asyncore.
858
859- Removed coupling between tests where one test failing could break
860 another.
861
862Tools
863
864- Ping added an interactive help browser to pydoc, fixed some nits
865 in the rest of the pydoc code, and added some features to his
866 inspect module.
867
868- An updated python-mode.el version 4.1 which integrates Ken
869 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
870 much nicer in XEmacs and Emacs. When stepping through your program
871 with pdb, in either the shell window or the *Python* window, the
872 source file and line will be tracked by an arrow. Very cool!
873
874- IDLE: syntax warnings in interactive mode are changed into errors.
875
876- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000877 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000878
879- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000880
Barry Warsaw11e89c72001-04-11 20:37:57 +0000881
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000882What's New in Python 2.1 beta 2?
883================================
884
Guido van Rossum053ae352001-03-22 14:17:21 +0000885(Unlisted are many fixed bugs, more documentation, etc.)
886
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000887Core language, builtins, and interpreter
888
Guido van Rossum053ae352001-03-22 14:17:21 +0000889- The nested scopes work (enabled by "from __future__ import
890 nested_scopes") is completed; in particular, the future now extends
891 into code executed through exec, eval() and execfile(), and into the
892 interactive interpreter.
893
894- When calling a base class method (e.g. BaseClass.__init__(self)),
895 this is now allowed even if self is not strictly spoken a class
896 instance (e.g. when using metaclasses or the Don Beaudry hook).
897
898- Slice objects are now comparable but not hashable; this prevents
899 dict[:] from being accepted but meaningless.
900
901- Complex division is now calculated using less braindead algorithms.
902 This doesn't change semantics except it's more likely to give useful
903 results in extreme cases. Complex repr() now uses full precision
904 like float repr().
905
906- sgmllib.py now calls handle_decl() for simple <!...> declarations.
907
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000908- It is illegal to assign to the name __debug__, which is set when the
909 interpreter starts. It is effectively a compile-time constant.
910
911- A warning will be issued if a global statement for a variable
912 follows a use or assignment of that variable.
913
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000914Standard library
915
Guido van Rossum053ae352001-03-22 14:17:21 +0000916- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
917 inspired by JUnit), is now part of the standard library. You now
918 have a choice of two testing frameworks: unittest requires you to
919 write testcases as separate code, doctest gathers them from
920 docstrings. Both approaches have their advantages and
921 disadvantages.
922
923- A new module Tix was added, which wraps the Tix extension library
924 for Tk. With that module, it is not necessary to statically link
925 Tix with _tkinter, since Tix will be loaded with Tcl's "package
926 require" command. See Demo/tix/.
927
928- tzparse.py is now obsolete.
929
930- In gzip.py, the seek() and tell() methods are removed -- they were
931 non-functional anyway, and it's better if callers can test for their
932 existence with hasattr().
933
934Python/C API
935
936- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
937 that's already in the dictionary during a PyDict_Next() iteration.
938 This used to fail occasionally when a dictionary resize operation
939 could be triggered that would rehash all the keys. All other
940 modifications to the dictionary are still off-limits during a
941 PyDict_Next() iteration!
942
943- New extended APIs related to passing compiler variables around.
944
945- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
946 implement isinstance() and issubclass().
947
948- Py_BuildValue() now has a "D" conversion to create a Python complex
949 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000950
Fred Drake4e262a92001-03-22 18:26:47 +0000951- Extensions types which support weak references must now set the
952 field allocated for the weak reference machinery to NULL themselves;
953 this is done to avoid the cost of checking each object for having a
954 weakly referencable type in PyObject_INIT(), since most types are
955 not weakly referencable.
956
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000957- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
958 free variables and cell variables to and from the frame's f_locals.
959
960- Variants of several functions defined in pythonrun.h have been added
961 to support the nested_scopes future statement. The variants all end
962 in Flags and take an extra argument, a PyCompilerFlags *; examples:
963 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
964 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000965 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000966
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000967Distutils
968
969- the sdist command now writes a PKG-INFO file, as described in PEP 241,
970 into the release tree.
971
Tim Peters0e57abf2001-05-02 07:39:38 +0000972- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000973 (an uninstaller, more customization of the installer's display)
974
975- from Jack Jansen: added Mac-specific code to generate a dialog for
976 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000977 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000978 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000979
980- added 'platforms' and 'keywords' to the set of metadata that can be
981 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000982
983- applied patches from Jason Tishler to make the compiler class work with
984 Cygwin.
985
986
Tim Peters2fe289a2001-03-01 22:19:38 +0000987What's New in Python 2.1 beta 1?
988================================
Tim Petersd66595f2001-02-04 03:09:53 +0000989
990Core language, builtins, and interpreter
991
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000992- Following an outcry from the community about the amount of code
993 broken by the nested scopes feature introduced in 2.1a2, we decided
994 to make this feature optional, and to wait until Python 2.2 (or at
995 least 6 months) to make it standard. The option can be enabled on a
996 per-module basis by adding "from __future__ import nested_scopes" at
997 the beginning of a module (before any other statements, but after
998 comments and an optional docstring). See PEP 236 (Back to the
999 __future__) for a description of the __future__ statement. PEP 227
1000 (Statically Nested Scopes) has been updated to reflect this change,
1001 and to clarify the semantics in a number of endcases.
1002
1003- The nested scopes code, when enabled, has been hardened, and most
1004 bugs and memory leaks in it have been fixed.
1005
1006- Compile-time warnings are now generated for a number of conditions
1007 that will break or change in meaning when nested scopes are enabled:
1008
1009 - Using "from...import *" or "exec" without in-clause in a function
1010 scope that also defines a lambda or nested function with one or
1011 more free (non-local) variables. The presence of the import* or
1012 bare exec makes it impossible for the compiler to determine the
1013 exact set of local variables in the outer scope, which makes it
1014 impossible to determine the bindings for free variables in the
1015 inner scope. To avoid the warning about import *, change it into
1016 an import of explicitly name object, or move the import* statement
1017 to the global scope; to avoid the warning about bare exec, use
1018 exec...in... (a good idea anyway -- there's a possibility that
1019 bare exec will be deprecated in the future).
1020
1021 - Use of a global variable in a nested scope with the same name as a
1022 local variable in a surrounding scope. This will change in
1023 meaning with nested scopes: the name in the inner scope will
1024 reference the variable in the outer scope rather than the global
1025 of the same name. To avoid the warning, either rename the outer
1026 variable, or use a global statement in the inner function.
1027
Neil Schemenauera35c6882001-02-27 04:45:05 +00001028- An optional object allocator has been included. This allocator is
1029 optimized for Python objects and should be faster and use less memory
1030 than the standard system allocator. It is not enabled by default
1031 because of possible thread safety problems. The allocator is only
1032 protected by the Python interpreter lock and it is possible that some
1033 extension modules require a thread safe allocator. The object
1034 allocator can be enabled by providing the "--with-pymalloc" option to
1035 configure.
1036
Tim Petersd66595f2001-02-04 03:09:53 +00001037Standard library
1038
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001039- pyexpat now detects the expat version if expat.h defines it. A
1040 number of additional handlers are provided, which are only available
1041 since expat 1.95. In addition, the methods SetParamEntityParsing and
1042 GetInputContext of Parser objects are available with 1.95.x
1043 only. Parser objects now provide the ordered_attributes and
1044 specified_attributes attributes. A new module expat.model was added,
1045 which offers a number of additional constants if 1.95.x is used.
1046
1047- xml.dom offers the new functions registerDOMImplementation and
1048 getDOMImplementation.
1049
1050- xml.dom.minidom offers a toprettyxml method. A number of DOM
1051 conformance issues have been resolved. In particular, Element now
1052 has an hasAttributes method, and the handling of namespaces was
1053 improved.
1054
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001055- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1056 getting information about live Python code, and pydoc.py, a module
1057 for interactively converting docstrings to HTML or text.
1058 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001059 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001060 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1061 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001062
Tim Peters1eff7962001-03-01 02:31:33 +00001063- New library module difflib.py, primarily packaging the SequenceMatcher
1064 class at the heart of the popular ndiff.py file-comparison tool.
1065
1066- doctest.py (a framework for verifying Python code examples in docstrings)
1067 is now part of the std library.
1068
Tim Petersd66595f2001-02-04 03:09:53 +00001069Windows changes
1070
Guido van Rossume3955a82001-03-02 14:05:59 +00001071- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1072 small GUI that lets you browse the module docstrings using your
1073 default web browser.
1074
Tim Peters1eff7962001-03-01 02:31:33 +00001075- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1076 Platforms) is implemented. See
1077
1078 http://python.sourceforge.net/peps/pep-0235.html
1079
1080 for full details, especially the "Current Lower-Left Semantics" section.
1081 The new Windows import rules are simpler than before:
1082
1083 A. If the PYTHONCASEOK environment variable exists, same as
1084 before: silently accept the first case-insensitive match of any
1085 kind; raise ImportError if none found.
1086
1087 B. Else search sys.path for the first case-sensitive match; raise
1088 ImportError if none found.
1089
1090 The same rules have been implented on other platforms with case-
1091 insensitive but case-preserving filesystems too (including Cygwin, and
1092 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001093
Tim Peters25a9ce32001-02-19 07:06:36 +00001094- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1095 what it's supposed to do (and does do under NT and 2000) via direct
1096 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001097 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001098 all Win9x systems before.
1099
Tim Peters1eff7962001-03-01 02:31:33 +00001100- Build: Subproject _test (effectively) renamed to _testcapi.
1101
Tim Peters2fe289a2001-03-01 22:19:38 +00001102New platforms
1103
1104- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1105 Thanks to Steven Majewski!
1106
1107- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1108 Tishler!
1109
Guido van Rossum9089b272001-03-02 06:49:50 +00001110- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1111 Schwertberger! See RISCOS/README for more information -- it seems
1112 that because of the bizarre filename conventions on RISCOS, no port
1113 to that platform is easy. Note that the new variable os.endsep is
1114 silently supported in order to make life easier on this platform,
1115 but we don't advertise it because it's not worth for most folks to
1116 care about RISCOS portability.
1117
Tim Peters25a9ce32001-02-19 07:06:36 +00001118
Tim Petersd7b5e882001-01-25 03:36:26 +00001119What's New in Python 2.1 alpha 2?
1120=================================
Tim Peters40ead762001-01-27 05:35:26 +00001121
Tim Petersd7b5e882001-01-25 03:36:26 +00001122Core language, builtins, and interpreter
1123
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001124- Scopes nest. If a name is used in a function or class, but is not
1125 local, the definition in the nearest enclosing function scope will
1126 be used. One consequence of this change is that lambda statements
1127 could reference variables in the namespaces where the lambda is
1128 defined. In some unusual cases, this change will break code.
1129
1130 In all previous version of Python, names were resolved in exactly
1131 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001132 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001133 function A is defined within a function B, the names bound in B are
1134 not visible in A. The new rules make names bound in B visible in A,
1135 unless A contains a name binding that hides the binding in B.
1136
1137 Section 4.1 of the reference manual describes the new scoping rules
1138 in detail. The test script in Lib/test/test_scope.py demonstrates
1139 some of the effects of the change.
1140
1141 The new rules will cause existing code to break if it defines nested
1142 functions where an outer function has local variables with the same
1143 name as globals or builtins used by the inner function. Example:
1144
1145 def munge(str):
1146 def helper(x):
1147 return str(x)
1148 if type(str) != type(''):
1149 str = helper(str)
1150 return str.strip()
1151
1152 Under the old rules, the name str in helper() is bound to the
1153 builtin function str(). Under the new rules, it will be bound to
1154 the argument named str and an error will occur when helper() is
1155 called.
1156
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001157- The compiler will report a SyntaxError if "from ... import *" occurs
1158 in a function or class scope. The language reference has documented
1159 that this case is illegal, but the compiler never checked for it.
1160 The recent introduction of nested scope makes the meaning of this
1161 form of name binding ambiguous. In a future release, the compiler
1162 may allow this form when there is no possibility of ambiguity.
1163
Tim Peters40ead762001-01-27 05:35:26 +00001164- repr(string) is easier to read, now using hex escapes instead of octal,
1165 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1166
1167 >>> "\texample \r\n" + chr(0) + chr(255)
1168 '\texample \r\n\x00\xff' # in 2.1
1169 '\011example \015\012\000\377' # in 2.0
1170
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001171- Functions are now compared and hashed by identity, not by value, since
1172 the func_code attribute is writable.
1173
Fred Drakefb9d7122001-02-01 20:00:40 +00001174- Weak references (PEP 205) have been added. This involves a few
1175 changes in the core, an extension module (_weakref), and a Python
1176 module (weakref). The weakref module is the public interface. It
1177 includes support for "explicit" weak references, proxy objects, and
1178 mappings with weakly held values.
1179
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001180- A 'continue' statement can now appear in a try block within the body
1181 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001182 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001183
Tim Petersd7b5e882001-01-25 03:36:26 +00001184Standard library
1185
Barry Warsaw30dbd142001-01-31 22:14:01 +00001186- mailbox.py now has a new class, PortableUnixMailbox which is
1187 identical to UnixMailbox but uses a more portable scheme for
1188 determining From_ separators. Also, the constructors for all the
1189 classes in this module have a new optional `factory' argument, which
1190 is a callable used when new message classes must be instantiated by
1191 the next() method.
1192
Tim Petersd7b5e882001-01-25 03:36:26 +00001193- random.py is now self-contained, and offers all the functionality of
1194 the now-deprecated whrandom.py. See the docs for details. random.py
1195 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001196 and restoring the internal state of the generator; and jumpahead(n),
1197 for quickly forcing the internal state to be the same as if n calls to
1198 random() had been made. The latter is particularly useful for multi-
1199 threaded programs, creating one instance of the random.Random() class for
1200 each thread, then using .jumpahead() to force each instance to use a
1201 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001202
Tim Peters0de88fc2001-02-01 04:59:18 +00001203- random.py's seed() function is new. For bit-for-bit compatibility with
1204 prior releases, use the whseed function instead. The new seed function
1205 addresses two problems: (1) The old function couldn't produce more than
1206 about 2**24 distinct internal states; the new one about 2**45 (the best
1207 that can be done in the Wichmann-Hill generator). (2) The old function
1208 sometimes produced identical internal states when passed distinct
1209 integers, and there was no simple way to predict when that would happen;
1210 the new one guarantees to produce distinct internal states for all
1211 arguments in [0, 27814431486576L).
1212
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001213- The socket module now supports raw packets on Linux. The socket
1214 family is AF_PACKET.
1215
Tim Peters9ea17ac2001-02-02 05:57:15 +00001216- test_capi.py is a start at running tests of the Python C API. The tests
1217 are implemented by the new Modules/_testmodule.c.
1218
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001219- A new extension module, _symtable, provides provisional access to the
1220 internal symbol table used by the Python compiler. A higher-level
1221 interface will be added on top of _symtable in a future release.
1222
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001223- Removed the obsolete soundex module.
1224
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001225- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1226 the isSameNode method; NamedNodeMap the get method.
1227
1228- xml.sax.expatreader supports the lexical handler property; it
1229 generates comment, startCDATA, and endCDATA events.
1230
Tim Petersee826f82001-01-31 19:39:44 +00001231Windows changes
1232
1233- Build procedure: the zlib project is built in a different way that
1234 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001235 the zlib binary used. See PCbuild\readme.txt for details. Your old
1236 zlib-related directories can be deleted; you'll need to download fresh
1237 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001238
Tim Peters9ea17ac2001-02-02 05:57:15 +00001239- Build: New subproject _test for the benefit of test_capi.py (see above).
1240
Tim Petersb16c56f2001-02-02 21:24:51 +00001241- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1242 interface to some Python compiler internals).
1243
1244- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001245 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001246
Tim Petersa3a3a032000-11-30 05:22:44 +00001247What's New in Python 2.1 alpha 1?
1248=================================
1249
1250Core language, builtins, and interpreter
1251
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001252- There is a new Unicode companion to the PyObject_Str() API
1253 called PyObject_Unicode(). It behaves in the same way as the
1254 former, but assures that the returned value is an Unicode object
1255 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001256
Guido van Rossumf98eda02001-01-17 15:54:45 +00001257- The comparison operators support "rich comparison overloading" (PEP
1258 207). C extension types can provide a rich comparison function in
1259 the new tp_richcompare slot in the type object. The cmp() function
1260 and the C function PyObject_Compare() first try the new rich
1261 comparison operators before trying the old 3-way comparison. There
1262 is also a new C API PyObject_RichCompare() (which also falls back on
1263 the old 3-way comparison, but does not constrain the outcome of the
1264 rich comparison to a Boolean result).
1265
1266 The rich comparison function takes two objects (at least one of
1267 which is guaranteed to have the type that provided the function) and
1268 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1269 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1270 object, which may be NotImplemented (in which case the tp_compare
1271 slot function is used as a fallback, if defined).
1272
1273 Classes can overload individual comparison operators by defining one
1274 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001275 __ge__. There are no explicit "reflected argument" versions of
1276 these; instead, __lt__ and __gt__ are each other's reflection,
1277 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1278 reflection (similar at the C level). No other implications are
1279 made; in particular, Python does not assume that == is the Boolean
1280 inverse of !=, or that < is the Boolean inverse of >=. This makes
1281 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001282
1283 Classes or types that want to implement (in)equality tests but not
1284 the ordering operators (i.e. unordered types) should implement ==
1285 and !=, and raise an error for the ordering operators.
1286
Guido van Rossuma88479f2001-01-18 14:28:08 +00001287 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001288 Boolean; e.g. a matrix type might want to return a matrix of bits
1289 for A < B, giving elementwise comparisons. Such types should ensure
1290 that any interpretation of their value in a Boolean context raises
1291 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1292 at the C level) to always raise an exception.
1293
Guido van Rossuma88479f2001-01-18 14:28:08 +00001294- Complex numbers use rich comparisons to define == and != but raise
1295 an exception for <, <=, > and >=. Unfortunately, this also means
1296 that cmp() of two complex numbers raises an exception when the two
1297 numbers differ. Since it is not mathematically meaningful to compare
1298 complex numbers except for equality, I hope that this doesn't break
1299 too much code.
1300
Tim Peters3389f192001-02-18 08:48:49 +00001301- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001302 not defined by the language, other than that it's arbitrary but
1303 consistent (see the Reference Manual). An implementation detail changed
1304 in 2.1a1 such that None now compares less than any other object. Code
1305 relying on this new behavior (like code that relied on the previous
1306 behavior) does so at its own risk.
1307
Barry Warsaw573b5412001-01-15 20:43:18 +00001308- Functions and methods now support getting and setting arbitrarily
1309 named attributes (PEP 232). Functions have a new __dict__
1310 (a.k.a. func_dict) which hold the function attributes. Methods get
1311 and set attributes on their underlying im_func. It is a TypeError
1312 to set an attribute on a bound method.
1313
Guido van Rossum051e3352001-01-15 19:11:10 +00001314- The xrange() object implementation has been improved so that
1315 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1316 limitation that in this case len(xrange(sys.maxint)) can't be
1317 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1318 work fine as long as the index i doesn't actually reach 2**31.
1319 (Python uses regular ints for sequence and string indices; fixing
1320 that is much more work.)
1321
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001322- Two changes to from...import:
1323
Guido van Rossumba381232001-02-03 15:06:40 +00001324 1) "from M import X" now works even if (after loading module M)
1325 sys.modules['M'] is not a real module; it's basically a getattr()
1326 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001327
1328 2) "from M import *" now looks for M.__all__ to decide which names to
1329 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1330 filters out names starting with '_' as before. Whether or not
1331 __all__ exists, there's no restriction on the type of M.
1332
Guido van Rossumf61f1662001-01-10 20:13:55 +00001333- File objects have a new method, xreadlines(). This is the fastest
1334 way to iterate over all lines in a file:
1335
1336 for line in file.xreadlines():
1337 ...do something to line...
1338
1339 See the xreadlines module (mentioned below) for how to do this for
1340 other file-like objects.
1341
1342- Even if you don't use file.xreadlines(), you may expect a speedup on
1343 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001344 quite a bit in platform-specific ways: on systems (like Linux) that
1345 support flockfile(), getc_unlocked(), and funlockfile(), those are
1346 used by default. On systems (like Windows) without getc_unlocked(),
1347 a complicated (but still thread-safe) method using fgets() is used by
1348 default.
1349
Tim Petersd52269b2001-01-25 06:23:18 +00001350 You can force use of the fgets() method by #define'ing
1351 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001352 getc_unlocked()).
1353
Tim Petersd52269b2001-01-25 06:23:18 +00001354 You can force fgets() not to be used by #define'ing
1355 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001356 test_bufio.py fails -- and let us know if it does!).
1357
1358- In addition, the fileinput module, while still slower than the other
1359 methods on most platforms, has been sped up too, by using
1360 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001361
1362- Support for run-time warnings has been added, including a new
1363 command line option (-W) to specify the disposition of warnings.
1364 See the description of the warnings module below.
1365
1366- Extensive changes have been made to the coercion code. This mostly
1367 affects extension modules (which can now implement mixed-type
1368 numerical operators without having to use coercion), but
1369 occasionally, in boundary cases the coercion semantics have changed
1370 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001371 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001372 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001373 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001374
Guido van Rossumf98eda02001-01-17 15:54:45 +00001375- In connection with the coercion changes, a new built-in singleton
1376 object, NotImplemented is defined. This can be returned for
1377 operations that wish to indicate they are not implemented for a
1378 particular combination of arguments. From C, this is
1379 Py_NotImplemented.
1380
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001381- The interpreter accepts now bytecode files on the command line even
1382 if they do not have a .pyc or .pyo extension. On Linux, after executing
1383
Martin v. Löwise214baa2001-02-04 22:37:56 +00001384import imp,sys,string
1385magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1386reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1387open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001388
1389 any byte code file can be used as an executable (i.e. as an argument
1390 to execve(2)).
1391
Tim Peters9940b802000-12-01 07:59:35 +00001392- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001393 character. In 1.6 and earlier, they never produced a sign,
1394 and raised an error if the value of the long was too large
1395 to fit in a Python int. In 2.0, they produced a sign if and
1396 only if too large to fit in an int. This was inconsistent
1397 across platforms (because the size of an int varies across
1398 platforms), and inconsistent with hex() and oct(). Example:
1399
1400 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001401 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001402 'ffffffbe' # in 2.0 and before, on 32-bit machines
1403 >>> hex(-0x42L)
1404 '-0x42L' # in all versions of Python
1405
Tim Peters9940b802000-12-01 07:59:35 +00001406 The behavior of %d formats for negative Python longs remains
1407 the same as in 2.0 (although in 1.6 and before, they raised
1408 an error if the long didn't fit in a Python int).
1409
1410 %u formats don't make sense for Python longs, but are allowed
1411 and treated the same as %d in 2.1. In 2.0, a negative long
1412 formatted via %u produced a sign if and only if too large to
1413 fit in an int. In 1.6 and earlier, a negative long formatted
1414 via %u raised an error if it was too big to fit in an int.
1415
Guido van Rossum3661d392000-12-12 22:10:31 +00001416- Dictionary objects have an odd new method, popitem(). This removes
1417 an arbitrary item from the dictionary and returns it (in the form of
1418 a (key, value) pair). This can be useful for algorithms that use a
1419 dictionary as a bag of "to do" items and repeatedly need to pick one
1420 item. Such algorithms normally end up running in quadratic time;
1421 using popitem() they can usually be made to run in linear time.
1422
Tim Peters36cdad12000-12-29 02:06:45 +00001423Standard library
1424
Thomas Woutersfe385252001-01-19 23:16:56 +00001425- In the time module, the time argument to the functions strftime,
1426 localtime, gmtime, asctime and ctime is now optional, defaulting to
1427 the current time (in the local timezone).
1428
Guido van Rossumda91f222001-01-15 16:36:08 +00001429- The ftplib module now defaults to passive mode, which is deemed a
1430 more useful default given that clients are often inside firewalls
1431 these days. Note that this could break if ftplib is used to connect
1432 to a *server* that is inside a firewall, from outside; this is
1433 expected to be a very rare situation. To fix that, you can call
1434 ftp.set_pasv(0).
1435
Martin v. Löwis10a27872001-01-13 09:54:41 +00001436- The module site now treats .pth files not only for path configuration,
1437 but also supports extensions to the initialization code: Lines starting
1438 with import are executed.
1439
Guido van Rossumf61f1662001-01-10 20:13:55 +00001440- There's a new module, warnings, which implements a mechanism for
1441 issuing and filtering warnings. There are some new built-in
1442 exceptions that serve as warning categories, and a new command line
1443 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1444 turns warnings into errors). warnings.warn(message[, category])
1445 issues a warning message; this can also be called from C as
1446 PyErr_Warn(category, message).
1447
1448- A new module xreadlines was added. This exports a single factory
1449 function, xreadlines(). The intention is that this code is the
1450 absolutely fastest way to iterate over all lines in an open
1451 file(-like) object:
1452
1453 import xreadlines
1454 for line in xreadlines.xreadlines(file):
1455 ...do something to line...
1456
1457 This is equivalent to the previous the speed record holder using
1458 file.readlines(sizehint). Note that if file is a real file object
1459 (as opposed to a file-like object), this is equivalent:
1460
1461 for line in file.xreadlines():
1462 ...do something to line...
1463
Tim Peters36cdad12000-12-29 02:06:45 +00001464- The bisect module has new functions bisect_left, insort_left,
1465 bisect_right and insort_right. The old names bisect and insort
1466 are now aliases for bisect_right and insort_right. XXX_right
1467 and XXX_left methods differ in what happens when the new element
1468 compares equal to one or more elements already in the list: the
1469 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001470 right. Code that doesn't care where equal elements end up should
1471 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001472
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001473- The new curses.panel module wraps the panel library that forms part
1474 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1475
Guido van Rossumf61f1662001-01-10 20:13:55 +00001476- The SocketServer module now sets the allow_reuse_address flag by
1477 default in the TCPServer class.
1478
1479- A new function, sys._getframe(), returns the stack frame pointer of
1480 the caller. This is intended only as a building block for
1481 higher-level mechanisms such as string interpolation.
1482
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001483- The pyexpat module supports a number of new handlers, which are
1484 available only in expat 1.2. If invocation of a callback fails, it
1485 will report an additional frame in the traceback. Parser objects
1486 participate now in garbage collection. If expat reports an unknown
1487 encoding, pyexpat will try to use a Python codec; that works only
1488 for single-byte charsets. The parser type objects is exposed as
1489 XMLParserObject.
1490
1491- xml.dom now offers standard definitions for symbolic node type and
1492 exception code constants, and a hierarchy of DOM exceptions. minidom
1493 was adjusted to use them.
1494
1495- The conformance of xml.dom.minidom to the DOM specification was
1496 improved. It detects a number of additional error cases; the
1497 previous/next relationship works even when the tree is modified;
1498 Node supports the normalize() method; NamedNodeMap, DocumentType and
1499 DOMImplementation classes were added; Element supports the
1500 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1501 method.
1502
Guido van Rossumf61f1662001-01-10 20:13:55 +00001503Build issues
1504
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001505- For Unix (and Unix-compatible) builds, configuration and building of
1506 extension modules is now greatly automated. Rather than having to
1507 edit the Modules/Setup file to indicate which modules should be
1508 built and where their include files and libraries are, a
1509 distutils-based setup.py script now takes care of building most
1510 extension modules. All extension modules built this way are built
1511 as shared libraries. Only a few modules that must be linked
1512 statically are still listed in the Setup file; you won't need to
1513 edit their configuration.
1514
1515- Python should now build out of the box on Cygwin. If it doesn't,
1516 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001517
1518- Python now always uses its own (renamed) implementation of getopt()
1519 -- there's too much variation among C library getopt()
1520 implementations.
1521
1522- C++ compilers are better supported; the CXX macro is always set to a
1523 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001524
Tim Petersd92dfe02000-12-12 01:18:41 +00001525Windows changes
1526
1527- select module: By default under Windows, a select() call
1528 can specify no more than 64 sockets. Python now boosts
1529 this Microsoft default to 512. If you need even more than
1530 that, see the MS docs (you'll need to #define FD_SETSIZE
1531 and recompile Python from source).
1532
Guido van Rossumf61f1662001-01-10 20:13:55 +00001533- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1534 subdirectory is no more!
1535
Tim Petersa3a3a032000-11-30 05:22:44 +00001536
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001537What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001538=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001539
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001540Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001541changes are in the file HISTORY. If you are making the jump directly
1542from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1543HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001544
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001545Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1546the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1547http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001548
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001549--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001550
1551======================================================================
1552
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001553What's new in 2.0 (since release candidate 1)?
1554==============================================
1555
1556Standard library
1557
1558- The copy_reg module was modified to clarify its intended use: to
1559 register pickle support for extension types, not for classes.
1560 pickle() will raise a TypeError if it is passed a class.
1561
1562- Fixed a bug in gettext's "normalize and expand" code that prevented
1563 it from finding an existing .mo file.
1564
1565- Restored support for HTTP/0.9 servers in httplib.
1566
Tim Peters989b7b92000-10-16 20:24:53 +00001567- The math module was changed to stop raising OverflowError in case of
1568 underflow, and return 0 instead in underflow cases. Whether Python
1569 used to raise OverflowError in case of underflow was platform-
1570 dependent (it did when the platform math library set errno to ERANGE
1571 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001572
1573- Fixed a bug in StringIO that occurred when the file position was not
1574 at the end of the file and write() was called with enough data to
1575 extend past the end of the file.
1576
1577- Fixed a bug that caused Tkinter error messages to get lost on
1578 Windows. The bug was fixed by replacing direct use of
1579 interp->result with Tcl_GetStringResult(interp).
1580
1581- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1582 redirect response.
1583
1584- Several changes were made to distutils: Some debugging code was
1585 removed from util. Fixed the installer used when an external zip
1586 program (like WinZip) is not found; the source code for this
1587 installer is in Misc/distutils. check_lib() was modified to behave
1588 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1589 test for whether installed modules are on sys.path was changed to
1590 use both normcase() and normpath().
1591
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001592- Several minor bugs were fixed in the xml package (the minidom,
1593 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001594
1595- The regression test driver (regrtest.py) behavior when invoked with
1596 -l changed: It now reports a count of objects that are recognized as
1597 garbage but not freed by the garbage collector.
1598
Tim Peters989b7b92000-10-16 20:24:53 +00001599- The regression test for the math module was changed to test
1600 exceptional behavior when the test is run in verbose mode. Python
1601 cannot yet guarantee consistent exception behavior across platforms,
1602 so the exception part of test_math is run only in verbose mode, and
1603 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001604
1605Internals
1606
1607- PyOS_CheckStack() has been disabled on Win64, where it caused
1608 test_sre to fail.
1609
1610Build issues
1611
1612- Changed compiler flags, so that gcc is always invoked with -Wall and
1613 -Wstrict-prototypes. Users compiling Python with GCC should see
1614 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001615 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001616 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001617
Tim Petersa3a3a032000-11-30 05:22:44 +00001618- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001619
1620Tools and other miscellany
1621
1622- The compiler in Tools/compiler was updated to support the new
1623 language features introduced in 2.0: extended print statement, list
1624 comprehensions, and augmented assignments. The new compiler should
1625 also be backwards compatible with Python 1.5.2; the compiler will
1626 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001627 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001628
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001629What's new in 2.0 release candidate 1 (since beta 2)?
1630=====================================================
1631
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001632What is release candidate 1?
1633
1634We believe that release candidate 1 will fix all known bugs that we
1635intend to fix for the 2.0 final release. This release should be a bit
1636more stable than the previous betas. We would like to see even more
1637widespread testing before the final release, so we are producing this
1638release candidate. The final release will be exactly the same unless
1639any show-stopping (or brown bag) bugs are found by testers of the
1640release candidate.
1641
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001642All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001643to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001644
1645Core language, builtins, and interpreter
1646
1647- A bug that caused crashes when __coerce__ was used with augmented
1648 assignment, e.g. +=, was fixed.
1649
1650- Raise ZeroDivisionError when raising zero to a negative number,
1651 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1652 power operator and the result of math.pow(0.0, -2.0) will vary by
1653 platform. On Linux, it raises a ValueError.
1654
1655- A bug in Unicode string interpolation was fixed that occasionally
1656 caused errors with formats including "%%". For example, the
1657 following expression "%% %s" % u"abc" no longer raises a TypeError.
1658
1659- Compilation of deeply nested expressions raises MemoryError instead
1660 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1661
1662- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1663 rendering them useless. They are now written in binary mode again.
1664
1665Standard library
1666
1667- Keyword arguments are now accepted for most pattern and match object
1668 methods in SRE, the standard regular expression engine.
1669
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001670- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001671 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001672
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001673- Several bugs in the Unicode handling and error handling in _tkinter
1674 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001675
1676- Fix memory management errors in Merge() and Tkapp_Call() routines.
1677
1678- Several changes were made to cStringIO to make it compatible with
1679 the file-like object interface and with StringIO. If operations are
1680 performed on a closed object, an exception is raised. The truncate
1681 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001682 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001683
1684- There were many changes made to the linuxaudiodev module and its
1685 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001686 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001687
1688 Note that this module is named poorly, because it should work
1689 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001690 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001691
1692 The module now raises exceptions when errors occur instead of
1693 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1694 audio) and defines a getptr() method that calls the
1695 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1696
1697- The library_version attribute, introduced in an earlier beta, was
1698 removed because it can not be supported with early versions of the C
1699 readline library, which provides no way to determine the version at
1700 compile-time.
1701
1702- The binascii module is now enabled on Win64.
1703
Tim Peters46446d62000-10-09 21:19:31 +00001704- tokenize.py no longer suffers "recursion depth" errors when parsing
1705 programs with very long string literals.
1706
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001707Internals
1708
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001709- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001710 which is called when the interpreter starts up to determine where
1711 the standard library is installed. These vulnerabilities affect all
1712 previous versions of Python and can be exploited by setting very
1713 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1714 setuid Python script, although use of the wrapper in
1715 Misc/setuid-prog.c will eliminate the vulnerability.
1716
1717- Fixed garbage collection bugs in instance creation that were
1718 triggered when errors occurred during initialization. The solution,
1719 applied in cPickle and in PyInstance_New(), is to call
1720 PyObject_GC_Init() after the initialization of the object's
1721 container attributes is complete.
1722
1723- pyexpat adds definitions of PyModule_AddStringConstant and
1724 PyModule_AddObject if the Python version is less than 2.0, which
1725 provides compatibility with PyXML on Python 1.5.2.
1726
1727- If the platform has a bogus definition for LONG_BIT (the number of
1728 bits in a long), an error will be reported at compile time.
1729
1730- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1731 collection crashes and possibly other, unreported crashes.
1732
1733- Fixed a memory leak in _PyUnicode_Fini().
1734
1735Build issues
1736
1737- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001738 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001739 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001740
1741- The mmap.PAGESIZE constant is now initialized using sysconf when
1742 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1743
1744- The md5 file should now compile on all platforms.
1745
1746- The select module now compiles on platforms that do not define
1747 POLLRDNORM and related constants.
1748
1749- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001750 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001751
Jeremy Hylton10921202000-10-09 18:34:12 +00001752- BeOS: A number of changes were made to the build and installation
1753 process. ar-fake now operates on a directory of object files.
1754 dl_export.h is gone, and its macros now appear on the mwcc command
1755 line during build on PPC BeOS.
1756
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001757- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001758 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001759
1760- Cygwin: Support for shared libraries, Tkinter, and sockets.
1761
1762- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1763
1764Tools and other miscellany
1765
1766- Removed debugging prints from main used with freeze.
1767
Tim Peters46446d62000-10-09 21:19:31 +00001768- IDLE auto-indent no longer crashes when it encounters Unicode
1769 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001770
1771What's new in 2.0 beta 2 (since beta 1)?
1772========================================
1773
1774Core language, builtins, and interpreter
1775
Tim Peters482c0212000-09-26 06:33:09 +00001776- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001777 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001778
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001779- Add -h and -V command line options to print the usage message and
1780 Python version number and exit immediately.
1781
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001782- eval() and exec accept Unicode objects as code parameters.
1783
1784- getattr() and setattr() now also accept Unicode objects for the
1785 attribute name, which are converted to strings using the default
1786 encoding before lookup.
1787
1788- Multiplication on string and Unicode now does proper bounds
1789 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1790 string is too long."
1791
1792- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001793 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001794
Jeremy Hylton1b618592000-09-26 05:32:36 +00001795
1796Standard library and extensions
1797
Guido van Rossum5b08f132001-04-16 02:05:23 +00001798- socket module: the OpenSSL code now adds support for RAND_status()
1799 and EGD (Entropy Gathering Device).
1800
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001801- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001802 argument checking; it still takes no arguments.
1803
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001804- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001805
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001806- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001807
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001808- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001809
1810- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001811 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001812
1813- copy: Copy Unicode objects atomically.
1814
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001815- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001816
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001817- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001818
Fred Drake67233bc2000-09-26 16:40:27 +00001819- dbm: Add get() and setdefault() methods to dbm object. Add constant
1820 `library' to module that names the library used. Added doc strings
1821 and method names to error messages. Uses configure to determine
1822 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1823 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001824
1825- distutils: Update to version 0.9.3.
1826
1827- dl: Add several dl.RTLD_ constants.
1828
1829- fpectl: Now supported on FreeBSD.
1830
1831- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1832 found by the collector will be saved in gc.garbage. This is useful
1833 for debugging a program that creates reference cycles.
1834
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001835- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001836 of HTTP class. Do not close socket on zero-length response. Do not
1837 crash when server sends invalid content-length header.
1838
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001839- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001840
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001841- marshal: When reading a short, sign-extend on platforms where shorts
1842 are bigger than 16 bits. When reading a long, repair the unportable
1843 sign extension that was being done for 64-bit machines. (It assumed
1844 that signed right shift sign-extends.)
1845
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001846- operator: Add contains(), invert(), __invert__() as aliases for
1847 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001848
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001849- os: Add support for popen2() and popen3() on all platforms where
1850 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001851
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001852- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001853 clicking on a file in Explorer (or passing the file name to the
1854 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001855
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001856- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001857 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001858
1859- pickle: Now raises ValueError when an invalid pickle that contains
1860 a non-string repr where a string repr was expected. This behavior
1861 matches cPickle.
1862
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001863- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001864
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001865- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001866
1867- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001868 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001869 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001870
1871- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001872 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001873
1874- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001875 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001876 few cycles during startup since the first call to
1877 setdefaultencoding() will initialize the codec registry and the
1878 encodings package.
1879
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001880- socket: Support for size hint in readlines() method of object returned
1881 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001882
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001883- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001884 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001885 is followed by whitespace.
1886
Tim Petersa3a3a032000-11-30 05:22:44 +00001887- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001888
1889- struct: Check ranges for bytes and shorts.
1890
1891- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001892 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001893
1894- Tkinter: Image objects are now guaranteed to have unique ids. Set
1895 event.delta to zero if Tk version doesn't support mousewheel.
1896 Removed some debugging prints.
1897
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001898- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001899
Fred Drake67233bc2000-09-26 16:40:27 +00001900- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001901 which works around a bug in Norton AntiVirus 2000 that leads directly
1902 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001903
1904- xml: New version detection code allows PyXML to override standard
1905 XML package if PyXML version is greater than 0.6.1.
1906
Fred Drake64bb3802000-09-26 16:21:35 +00001907- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1908 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1909 tree only for nodes which are sufficiently interesting to a specific
1910 application. Does not provide the HTML-specific extensions. Still
1911 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001912
Fred Drake64bb3802000-09-26 16:21:35 +00001913- xml.sax: SAX 2 support for Python, including all the handler
1914 interfaces needed to process XML 1.0 compliant XML. Some
1915 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001916
Fred Drake64bb3802000-09-26 16:21:35 +00001917- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1918 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001919
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001920
Jeremy Hylton1b618592000-09-26 05:32:36 +00001921C API
1922
1923- Add three new convenience functions for module initialization --
1924 PyModule_AddObject(), PyModule_AddIntConstant(), and
1925 PyModule_AddStringConstant().
1926
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001927- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001928 removed and add #error to Python.h if NULL isn't defined after
1929 #include of stdio.h.
1930
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001931- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001932 backwards compatibility (at the source level) with old extensions.
1933
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001934- A wrapper API was added for signal() and sigaction(). Instead of
1935 either function, always use PyOS_getsig() to get a signal handler
1936 and PyOS_setsig() to set one. A new convenience typedef
1937 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001938
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001939- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001940 internal data buffer and size of a string object -- or the default
1941 encoded version of a Unicode object.
1942
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001943- PyString_Size() and PyString_AsString() accept Unicode objects.
1944
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001945- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001946 exists). INT_MAX and LONG_MAX will always be defined, even if
1947 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001948
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001949- PyFloat_FromString takes a second argument, pend, that was
1950 effectively useless. It is now officially useless but preserved for
1951 backwards compatibility. If the pend argument is not NULL, *pend is
1952 set to NULL.
1953
1954- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1955 for the attribute name. See note on getattr() above.
1956
1957- A few bug fixes to argument processing for Unicode.
1958 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1959 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1960 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001961 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001962
1963- Py_BuildValue accepts B format (for bgen-generated code).
1964
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001965
Jeremy Hylton1b618592000-09-26 05:32:36 +00001966Internals
1967
1968- On Unix, fix code for finding Python installation directory so that
1969 it works when argv[0] is a relative path.
1970
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001971- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001972 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001973 rather than by generating a copy of the object.
1974
Tim Peters482c0212000-09-26 06:33:09 +00001975- Several of the internal Unicode tables are much smaller now, and
1976 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001977
Jeremy Hylton97693b02000-09-26 17:42:51 +00001978- In the garbage collector: Fixed bug in collection of tuples. Fixed
1979 bug that caused some instances to be removed from the container set
1980 while they were still live. Fixed parsing in gc.set_debug() for
1981 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001982
1983- Fixed refcount problem in instance deallocation that only occurred
1984 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1985
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001986- On Windows, getpythonregpath is now protected against null data in
1987 registry key.
1988
1989- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001990 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001991
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001992
Jeremy Hylton1b618592000-09-26 05:32:36 +00001993Build and platform-specific issues
1994
1995- Better support of GNU Pth via --with-pth configure option.
1996
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001997- Python/C API now properly exposed to dynamically-loaded extension
1998 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001999
2000- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2001 Don't define MS_SYNC to be zero when it is undefined. Added missing
2002 prototypes in posixmodule.c.
2003
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002004- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002005 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002006
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002007- Fix largefile support on older NetBSD systems and OpenBSD by adding
2008 define for TELL64.
2009
2010
2011Tools and other miscellany
2012
2013- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2014
2015- freeze: The modulefinder now works with 2.0 opcodes.
2016
Tim Petersa3a3a032000-11-30 05:22:44 +00002017- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002018 Move hackery of sys.argv until after the Tk instance has been
2019 created, which allows the application-specific Tkinter
2020 initialization to be executed if present; also pass an explicit
2021 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002022
Jeremy Hylton1b618592000-09-26 05:32:36 +00002023
2024What's new in 2.0 beta 1?
2025=========================
2026
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002027Source Incompatibilities
2028------------------------
2029
2030None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2031such as single-argument append(), connect() and bind(), and changes to
2032str(long) and repr(float).
2033
2034
2035Binary Incompatibilities
2036------------------------
2037
2038- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2039with Python 2.0; these extensions will have to be rebuilt for Python
20402.0.
2041
2042- On Windows, attempting to import a third party extension built for
2043Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2044can do about this. Check your PYTHONPATH environment variable!
2045
2046- Python bytecode files (*.pyc and *.pyo) are not compatible between
2047releases.
2048
2049
2050Overview of Changes Since 1.6
2051-----------------------------
2052
2053There are many new modules (including brand new XML support through
2054the xml package, and i18n support through the gettext module); a list
2055of all new modules is included below. Lots of bugs have been fixed.
2056
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002057The process for making major new changes to the language has changed
2058since Python 1.6. Enhancements must now be documented by a Python
2059Enhancement Proposal (PEP) before they can be accepted.
2060
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002061There are several important syntax enhancements, described in more
2062detail below:
2063
2064 - Augmented assignment, e.g. x += 1
2065
2066 - List comprehensions, e.g. [x**2 for x in range(10)]
2067
2068 - Extended import statement, e.g. import Module as Name
2069
2070 - Extended print statement, e.g. print >> file, "Hello"
2071
2072Other important changes:
2073
2074 - Optional collection of cyclical garbage
2075
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002076Python Enhancement Proposal (PEP)
2077---------------------------------
2078
2079PEP stands for Python Enhancement Proposal. A PEP is a design
2080document providing information to the Python community, or describing
2081a new feature for Python. The PEP should provide a concise technical
2082specification of the feature and a rationale for the feature.
2083
2084We intend PEPs to be the primary mechanisms for proposing new
2085features, for collecting community input on an issue, and for
2086documenting the design decisions that have gone into Python. The PEP
2087author is responsible for building consensus within the community and
2088documenting dissenting opinions.
2089
2090The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002091
2092Augmented Assignment
2093--------------------
2094
2095This must have been the most-requested feature of the past years!
2096Eleven new assignment operators were added:
2097
Guido van Rossume905e952000-09-05 12:42:46 +00002098 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002099
2100For example,
2101
2102 A += B
2103
2104is similar to
2105
2106 A = A + B
2107
2108except that A is evaluated only once (relevant when A is something
2109like dict[index].attr).
2110
2111However, if A is a mutable object, A may be modified in place. Thus,
2112if A is a number or a string, A += B has the same effect as A = A+B
2113(except A is only evaluated once); but if a is a list, A += B has the
2114same effect as A.extend(B)!
2115
2116Classes and built-in object types can override the new operators in
2117order to implement the in-place behavior; the not-in-place behavior is
2118used automatically as a fallback when an object doesn't implement the
2119in-place behavior. For classes, the method name is derived from the
2120method name for the corresponding not-in-place operator by inserting
2121an 'i' in front of the name, e.g. __iadd__ implements in-place
2122__add__.
2123
2124Augmented assignment was implemented by Thomas Wouters.
2125
2126
2127List Comprehensions
2128-------------------
2129
2130This is a flexible new notation for lists whose elements are computed
2131from another list (or lists). The simplest form is:
2132
2133 [<expression> for <variable> in <sequence>]
2134
Guido van Rossum56db0952000-09-06 23:34:25 +00002135For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002136This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002137
2138You can also add a condition:
2139
2140 [<expression> for <variable> in <sequence> if <condition>]
2141
2142For example, [w for w in words if w == w.lower()] would yield the list
2143of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002144than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002145
2146You can also have nested for loops and more than one 'if' clause. For
2147example, here's a function that flattens a sequence of sequences::
2148
2149 def flatten(seq):
2150 return [x for subseq in seq for x in subseq]
2151
2152 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2153
2154This prints
2155
2156 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2157
2158List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002159Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002160
2161
2162Extended Import Statement
2163-------------------------
2164
2165Many people have asked for a way to import a module under a different
2166name. This can be accomplished like this:
2167
2168 import foo
2169 bar = foo
2170 del foo
2171
2172but this common idiom gets old quickly. A simple extension of the
2173import statement now allows this to be written as follows:
2174
2175 import foo as bar
2176
2177There's also a variant for 'from ... import':
2178
2179 from foo import bar as spam
2180
2181This also works with packages; e.g. you can write this:
2182
2183 import test.regrtest as regrtest
2184
2185Note that 'as' is not a new keyword -- it is recognized only in this
2186context (this is only possible because the syntax for the import
2187statement doesn't involve expressions).
2188
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002189Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002190
2191
2192Extended Print Statement
2193------------------------
2194
2195Easily the most controversial new feature, this extension to the print
2196statement adds an option to make the output go to a different file
2197than the default sys.stdout.
2198
2199For example, to write an error message to sys.stderr, you can now
2200write:
2201
2202 print >> sys.stderr, "Error: bad dog!"
2203
2204As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002205evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002206
2207 print >> None, "Hello world"
2208
2209is equivalent to
2210
2211 print "Hello world"
2212
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002213Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002214
2215
2216Optional Collection of Cyclical Garbage
2217---------------------------------------
2218
2219Python is now equipped with a garbage collector that can hunt down
2220cyclical references between Python objects. It's no replacement for
2221reference counting; in fact, it depends on the reference counts being
2222correct, and decides that a set of objects belong to a cycle if all
2223their reference counts can be accounted for from their references to
2224each other. This devious scheme was first proposed by Eric Tiedemann,
2225and brought to implementation by Neil Schemenauer.
2226
2227There's a module "gc" that lets you control some parameters of the
2228garbage collection. There's also an option to the configure script
2229that lets you enable or disable the garbage collection. In 2.0b1,
2230it's on by default, so that we (hopefully) can collect decent user
2231experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002232performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002233off by default in the final 2.0 release.
2234
2235
2236Smaller Changes
2237---------------
2238
2239A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2240map(None, seq1, seq2, ...) when the sequences have the same length;
2241i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2242the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002243zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002244
2245sys.version_info is a tuple (major, minor, micro, level, serial).
2246
2247Dictionaries have an odd new method, setdefault(key, default).
2248dict.setdefault(key, default) returns dict[key] if it exists; if not,
2249it sets dict[key] to default and returns that value. Thus:
2250
2251 dict.setdefault(key, []).append(item)
2252
2253does the same work as this common idiom:
2254
2255 if not dict.has_key(key):
2256 dict[key] = []
2257 dict[key].append(item)
2258
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002259There are two new variants of SyntaxError that are raised for
2260indentation-related errors: IndentationError and TabError.
2261
2262Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2263escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002264
2265The limits on the size of expressions and file in Python source code
2266have been raised from 2**16 to 2**32. Previous versions of Python
2267were limited because the maximum argument size the Python VM accepted
2268was 2**16. This limited the size of object constructor expressions,
2269e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2270limit was raised thanks to a patch by Charles Waldman that effectively
2271fixes the problem. It is now much more likely that you will be
2272limited by available memory than by an arbitrary limit in Python.
2273
2274The interpreter's maximum recursion depth can be modified by Python
2275programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2276limit is the maximum number of recursive calls that can be made by
2277Python code. The limit exists to prevent infinite recursion from
2278overflowing the C stack and causing a core dump. The default value is
22791000. The maximum safe value for a particular platform can be found
2280by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002281
2282New Modules and Packages
2283------------------------
2284
2285atexit - for registering functions to be called when Python exits.
2286
2287imputil - Greg Stein's alternative API for writing custom import
2288hooks.
2289
2290pyexpat - an interface to the Expat XML parser, contributed by Paul
2291Prescod.
2292
2293xml - a new package with XML support code organized (so far) in three
2294subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2295would fill a volume. There's a special feature whereby a
2296user-installed package named _xmlplus overrides the standard
2297xmlpackage; this is intended to give the XML SIG a hook to distribute
2298backwards-compatible updates to the standard xml package.
2299
2300webbrowser - a platform-independent API to launch a web browser.
2301
2302
Guido van Rossume905e952000-09-05 12:42:46 +00002303Changed Modules
2304---------------
2305
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002306array -- new methods for array objects: count, extend, index, pop, and
2307remove
2308
2309binascii -- new functions b2a_hex and a2b_hex that convert between
2310binary data and its hex representation
2311
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002312calendar -- Many new functions that support features including control
2313over which day of the week is the first day, returning strings instead
2314of printing them. Also new symbolic constants for days of week,
2315e.g. MONDAY, ..., SUNDAY.
2316
2317cgi -- FieldStorage objects have a getvalue method that works like a
2318dictionary's get method and returns the value attribute of the object.
2319
2320ConfigParser -- The parser object has new methods has_option,
2321remove_section, remove_option, set, and write. They allow the module
2322to be used for writing config files as well as reading them.
2323
2324ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002325optionally support the RFC 959 REST command.
2326
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002327gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002328
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002329httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2330the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002331
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002332locale -- implement getdefaultlocale for Win32 and Macintosh
2333
2334marshal -- no longer dumps core when marshaling deeply nested or
2335recursive data structures
2336
2337os -- new functions isatty, seteuid, setegid, setreuid, setregid
2338
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002339os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2340support under Unix.
2341
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002342os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002343
2344os.path -- fix semantics of os.path.commonprefix
2345
2346smtplib -- support for sending very long messages
2347
2348socket -- new function getfqdn()
2349
2350readline -- new functions to read, write and truncate history files.
2351The readline section of the library reference manual contains an
2352example.
2353
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002354select -- add interface to poll system call
2355
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002356shutil -- new copyfileobj function
2357
2358SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2359HTTP server.
2360
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002361Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002362
2363urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002364e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002365
2366whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002367
2368
2369Obsolete Modules
2370----------------
2371
2372None. However note that 1.6 made a whole slew of modules obsolete:
2373stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2374poly, zmod, strop, util, whatsound.
2375
2376
2377Changed, New, Obsolete Tools
2378----------------------------
2379
Tim Peters8b092332000-09-05 20:15:25 +00002380None.
Guido van Rossume905e952000-09-05 12:42:46 +00002381
2382
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002383C-level Changes
2384---------------
2385
2386Several cleanup jobs were carried out throughout the source code.
2387
2388All C code was converted to ANSI C; we got rid of all uses of the
2389Py_PROTO() macro, which makes the header files a lot more readable.
2390
2391Most of the portability hacks were moved to a new header file,
2392pyport.h; several other new header files were added and some old
2393header files were removed, in an attempt to create a more rational set
2394of header files. (Few of these ever need to be included explicitly;
2395they are all included by Python.h.)
2396
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002397Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002398and Win64, especially for the new Intel Itanium processor. Mick also
2399added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002400
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002401The C APIs to return an object's size have been update to consistently
2402use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2403previous versions, the abstract interfaces used PyXXX_Length and the
2404concrete interfaces used PyXXX_Size. The old names,
2405e.g. PyObject_Length, are still available for backwards compatibility
2406at the API level, but are deprecated.
2407
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002408The PyOS_CheckStack function has been implemented on Windows by
2409Fredrik Lundh. It prevents Python from failing with a stack overflow
2410on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002411
2412The GC changes resulted in creation of two new slots on object,
2413tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002414the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002415
2416The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002417C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002418
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002419PyErr_Format has been updated to automatically calculate the size of
2420the buffer needed to hold the formatted result string. This change
2421prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002422
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002423New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002424
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002425PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2426that are the same as their non-Ex counterparts except they take an
2427extra flag argument that tells them to close the file when done.
2428
2429XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002430
Tim Peters8b092332000-09-05 20:15:25 +00002431
2432Windows Changes
2433---------------
2434
2435New popen2/popen3/peopen4 in os module (see Changed Modules above).
2436
2437os.popen is much more usable on Windows 95 and 98. See Microsoft
2438Knowledge Base article Q150956. The Win9x workaround described there
2439is implemented by the new w9xpopen.exe helper in the root of your
2440Python installation. Note that Python uses this internally; it is not
2441a standalone program.
2442
2443Administrator privileges are no longer required to install Python
2444on Windows NT or Windows 2000. If you have administrator privileges,
2445Python's registry info will be written under HKEY_LOCAL_MACHINE.
2446Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002447under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002448uses of Python, but will prevent some advanced uses from working
2449(for example, running a Python script as an NT service, or possibly
2450from CGI).
2451
2452[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2453installer; instead, it installs the needed Tcl/Tk files directly in the
2454Python directory. If you already have a Tcl/Tk installation, this
2455wastes some disk space (about 4 Megs) but avoids problems with
2456conflicting Tcl/Tk installations, and makes it much easier for Python
2457to ensure that Tcl/Tk can find all its files.
2458
2459[This was new in 1.6] The Windows installer now installs by default in
2460\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2461
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002462
2463Updates to the changes between 1.5.2 and 1.6
2464--------------------------------------------
2465
2466The 1.6 NEWS file can't be changed after the release is done, so here
2467is some late-breaking news:
2468
2469New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2470and changes to getlocale() and setlocale().
2471
2472The new module is now enabled per default.
2473
2474It is not true that the encodings codecs cannot be used for normal
2475strings: the string.encode() (which is also present on 8-bit strings
2476!) allows using them for 8-bit strings too, e.g. to convert files from
2477cp1252 (Windows) to latin-1 or vice-versa.
2478
2479Japanese codecs are available from Tamito KAJIYAMA:
2480http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2481
2482
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002483======================================================================