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Giampaolo Rodolà3108f982011-02-24 20:59:48 +00001****************************
2 What's New In Python 3.3
3****************************
4
5:Author: Raymond Hettinger
6:Release: |release|
7:Date: |today|
8
9.. $Id$
10 Rules for maintenance:
11
12 * Anyone can add text to this document. Do not spend very much time
13 on the wording of your changes, because your text will probably
14 get rewritten to some degree.
15
16 * The maintainer will go through Misc/NEWS periodically and add
17 changes; it's therefore more important to add your changes to
18 Misc/NEWS than to this file.
19
20 * This is not a complete list of every single change; completeness
21 is the purpose of Misc/NEWS. Some changes I consider too small
22 or esoteric to include. If such a change is added to the text,
23 I'll just remove it. (This is another reason you shouldn't spend
24 too much time on writing your addition.)
25
26 * If you want to draw your new text to the attention of the
27 maintainer, add 'XXX' to the beginning of the paragraph or
28 section.
29
30 * It's OK to just add a fragmentary note about a change. For
31 example: "XXX Describe the transmogrify() function added to the
32 socket module." The maintainer will research the change and
33 write the necessary text.
34
35 * You can comment out your additions if you like, but it's not
36 necessary (especially when a final release is some months away).
37
38 * Credit the author of a patch or bugfix. Just the name is
39 sufficient; the e-mail address isn't necessary.
40
41 * It's helpful to add the bug/patch number as a comment:
42
43 % Patch 12345
44 XXX Describe the transmogrify() function added to the socket
45 module.
46 (Contributed by P.Y. Developer.)
47
48 This saves the maintainer the effort of going through the SVN log
49 when researching a change.
50
51This article explains the new features in Python 3.3, compared to 3.2.
52
53
54PEP XXX: Stub
55=============
56
57
58Other Language Changes
59======================
60
61Some smaller changes made to the core Python language are:
62
63* Stub
64
65
66New, Improved, and Deprecated Modules
67=====================================
68
69* Stub
70
Victor Stinner2cded9c2011-07-08 01:45:13 +020071codecs
72------
73
74Multibyte CJK decoders now resynchronize faster. They only ignore the first
Georg Brandl6c0929b2011-07-09 11:43:33 +020075byte of an invalid byte sequence. For example, ``b'\xff\n'.decode('gb2312',
76'replace')`` now returns a ``\n`` after the replacement character.
Victor Stinner2cded9c2011-07-08 01:45:13 +020077
Georg Brandl6c0929b2011-07-09 11:43:33 +020078(:issue:`12016`)
Victor Stinner2cded9c2011-07-08 01:45:13 +020079
80Don't reset incremental encoders of CJK codecs at each call to their encode()
Georg Brandl6c0929b2011-07-09 11:43:33 +020081method anymore. For example::
Victor Stinner2cded9c2011-07-08 01:45:13 +020082
83 $ ./python -q
84 >>> import codecs
85 >>> encoder = codecs.getincrementalencoder('hz')('strict')
86 >>> b''.join(encoder.encode(x) for x in '\u52ff\u65bd\u65bc\u4eba\u3002 Bye.')
87 b'~{NpJ)l6HK!#~} Bye.'
88
Georg Brandl6c0929b2011-07-09 11:43:33 +020089This example gives ``b'~{Np~}~{J)~}~{l6~}~{HK~}~{!#~} Bye.'`` with older Python
Victor Stinner2cded9c2011-07-08 01:45:13 +020090versions.
91
Georg Brandl6c0929b2011-07-09 11:43:33 +020092(:issue:`12100`)
Victor Stinner2cded9c2011-07-08 01:45:13 +020093
Éric Araujo84b8ed82011-08-29 21:42:47 +020094crypt
95-----
96
97Addition of salf and modular crypt format to the :mod:`crypt` module.
98
99(:issue:`10924`)
100
Victor Stinnera7878b72011-07-14 23:07:44 +0200101curses
102------
103
Éric Araujocdb31092011-07-28 23:10:25 +0200104The :class:`curses.window` class has a new :meth:`~curses.window.get_wch` method
105to get a wide character. Patch by Iñigo Serna.
Victor Stinnera7878b72011-07-14 23:07:44 +0200106
107(:issue:`6755`)
108
Victor Stinner024e37a2011-03-31 01:31:06 +0200109faulthandler
110------------
111
112New module: :mod:`faulthandler`.
113
114 * :envvar:`PYTHONFAULTHANDLER`
115 * :option:`-X` ``faulthandler``
116
Victor Stinnerfa0e3d52011-05-09 01:01:09 +0200117
Victor Stinner811db3b2011-09-21 03:20:03 +0200118ftplib
119------
120
121The :class:`~ftplib.FTP_TLS` class now provides a new
122:func:`~ftplib.FTP_TLS.ccc` function to revert control channel back to
123plaintex. This can be useful to take advantage of firewalls that know how to
124handle NAT with non-secure FTP without opening fixed ports.
125
126(Contributed by Giampaolo Rodolà in :issue:`12139`)
127
128
Victor Stinnerfa0e3d52011-05-09 01:01:09 +0200129math
130----
131
132The :mod:`math` module has a new function:
133
134 * :func:`~math.log2`: return the base-2 logarithm of *x*
135 (Written by Mark Dickinson in :issue:`11888`).
136
137
138nntplib
139-------
140
141The :class:`nntplib.NNTP` class now supports the context manager protocol to
142unconditionally consume :exc:`socket.error` exceptions and to close the NNTP
143connection when done::
144
145 >>> from nntplib import NNTP
Ezio Melotti3c14b4e2011-07-13 11:44:44 +0300146 >>> with NNTP('news.gmane.org') as n:
Victor Stinnerfa0e3d52011-05-09 01:01:09 +0200147 ... n.group('gmane.comp.python.committers')
148 ...
Ezio Melotti04f648c2011-07-26 09:37:46 +0300149 ('211 1755 1 1755 gmane.comp.python.committers', 1755, 1, 1755, 'gmane.comp.python.committers')
Victor Stinnerfa0e3d52011-05-09 01:01:09 +0200150 >>>
151
152(Contributed by Giampaolo Rodolà in :issue:`9795`)
153
154
Giampaolo Rodolàc9c2c8b2011-02-25 14:39:16 +0000155os
156--
157
Charles-François Natalia003af12011-06-01 20:30:52 +0200158* The :mod:`os` module has a new :func:`~os.pipe2` function that makes it
159 possible to create a pipe with :data:`~os.O_CLOEXEC` or
160 :data:`~os.O_NONBLOCK` flags set atomically. This is especially useful to
161 avoid race conditions in multi-threaded programs.
162
Giampaolo Rodolà18e8bcb2011-02-25 20:57:54 +0000163* The :mod:`os` module has a new :func:`~os.sendfile` function which provides
164 an efficent "zero-copy" way for copying data from one file (or socket)
165 descriptor to another. The phrase "zero-copy" refers to the fact that all of
166 the copying of data between the two descriptors is done entirely by the
167 kernel, with no copying of data into userspace buffers. :func:`~os.sendfile`
168 can be used to efficiently copy data from a file on disk to a network socket,
169 e.g. for downloading a file.
Giampaolo Rodolàc9c2c8b2011-02-25 14:39:16 +0000170
Giampaolo Rodolà18e8bcb2011-02-25 20:57:54 +0000171 (Patch submitted by Ross Lagerwall and Giampaolo Rodolà in :issue:`10882`.)
172
173* The :mod:`os` module has two new functions: :func:`~os.getpriority` and
174 :func:`~os.setpriority`. They can be used to get or set process
175 niceness/priority in a fashion similar to :func:`os.nice` but extended to all
176 processes instead of just the current one.
177
178 (Patch submitted by Giampaolo Rodolà in :issue:`10784`.)
Giampaolo Rodolà3108f982011-02-24 20:59:48 +0000179
Giampaolo Rodolà424298a2011-03-03 18:34:06 +0000180
Éric Araujo765e94f2011-06-03 17:26:59 +0200181packaging
182---------
183
184:mod:`distutils` has undergone additions and refactoring under a new name,
185:mod:`packaging`, to allow developers to break backward compatibility.
186:mod:`distutils` is still provided in the standard library, but users are
187encouraged to transition to :mod:`packaging`. For older versions of Python, a
188backport compatible with 2.4+ and 3.1+ will be made available on PyPI under the
189name :mod:`distutils2`.
190
191.. TODO add examples and howto to the packaging docs and link to them
192
193
Victor Stinner383c3fc2011-05-25 01:35:05 +0200194pydoc
195-----
196
Victor Stinner6daa33c2011-05-25 01:41:22 +0200197The Tk GUI and the :func:`~pydoc.serve` function have been removed from the
198:mod:`pydoc` module: ``pydoc -g`` and :func:`~pydoc.serve` have been deprecated
199in Python 3.2.
Victor Stinner383c3fc2011-05-25 01:35:05 +0200200
201
Victor Stinnerd5c355c2011-04-30 14:53:09 +0200202sys
203---
Victor Stinner754851f2011-04-19 23:58:51 +0200204
Éric Araujo84b8ed82011-08-29 21:42:47 +0200205* The :mod:`sys` module has a new :data:`~sys.thread_info` :term:`struct
Victor Stinnerd5c355c2011-04-30 14:53:09 +0200206 sequence` holding informations about the thread implementation.
Victor Stinner754851f2011-04-19 23:58:51 +0200207
Georg Brandl00db5822011-04-30 15:30:03 +0200208 (:issue:`11223`)
Victor Stinnera9293352011-04-30 15:21:58 +0200209
Victor Stinnerfa0e3d52011-05-09 01:01:09 +0200210
Victor Stinnera9293352011-04-30 15:21:58 +0200211signal
212------
213
Victor Stinnerfa0e3d52011-05-09 01:01:09 +0200214* The :mod:`signal` module has new functions:
Victor Stinnera9293352011-04-30 15:21:58 +0200215
Victor Stinnerb3e72192011-05-08 01:46:11 +0200216 * :func:`~signal.pthread_sigmask`: fetch and/or change the signal mask of the
217 calling thread (Contributed by Jean-Paul Calderone in :issue:`8407`) ;
218 * :func:`~signal.pthread_kill`: send a signal to a thread ;
219 * :func:`~signal.sigpending`: examine pending functions ;
220 * :func:`~signal.sigwait`: wait a signal.
Ross Lagerwallbc808222011-06-25 12:13:40 +0200221 * :func:`~signal.sigwaitinfo`: wait for a signal, returning detailed
222 information about it.
223 * :func:`~signal.sigtimedwait`: like :func:`~signal.sigwaitinfo` but with a
224 timeout.
Victor Stinnera9293352011-04-30 15:21:58 +0200225
Victor Stinnerd49b1f12011-05-08 02:03:15 +0200226* The signal handler writes the signal number as a single byte instead of
227 a nul byte into the wakeup file descriptor. So it is possible to wait more
228 than one signal and know which signals were raised.
229
Victor Stinner388196e2011-05-10 17:13:00 +0200230* :func:`signal.signal` and :func:`signal.siginterrupt` raise an OSError,
231 instead of a RuntimeError: OSError has an errno attribute.
232
Nick Coghlan96fe56a2011-08-22 11:55:57 +1000233socket
234------
235
236The :class:`~socket.socket` class now exposes addititonal methods to
237process ancillary data when supported by the underlying platform:
238
239* :func:`~socket.socket.sendmsg`
240* :func:`~socket.socket.recvmsg`
241* :func:`~socket.socket.recvmsg_into`
242
243(Contributed by David Watson in :issue:`6560`, based on an earlier patch
244by Heiko Wundram)
Victor Stinner754851f2011-04-19 23:58:51 +0200245
Victor Stinner99c8b162011-05-24 12:05:19 +0200246ssl
247---
248
249The :mod:`ssl` module has new functions:
250
251 * :func:`~ssl.RAND_bytes`: generate cryptographically strong
252 pseudo-random bytes.
253 * :func:`~ssl.RAND_pseudo_bytes`: generate pseudo-random bytes.
254
255
Victor Stinner811db3b2011-09-21 03:20:03 +0200256struct
Giampaolo Rodola'096dcb12011-06-27 11:17:51 +0200257------
258
Victor Stinner811db3b2011-09-21 03:20:03 +0200259The :mod:`struct` module supports the :c:type:`long long` type using ``q`` and
260``Q`` type codes.
Giampaolo Rodola'096dcb12011-06-27 11:17:51 +0200261
Victor Stinner811db3b2011-09-21 03:20:03 +0200262(Contributed by Oren Tirosh and Hirokazu Yamamoto in :issue:`1172711`)
Giampaolo Rodola'210e7ca2011-07-01 13:55:36 +0200263
264
265shutil
266------
267
Sandro Tosiaec2f212011-08-23 00:58:21 +0200268* The :mod:`shutil` module has these new fuctions:
Giampaolo Rodola'210e7ca2011-07-01 13:55:36 +0200269
Sandro Tosiaec2f212011-08-23 00:58:21 +0200270 * :func:`~shutil.disk_usage`: provides total, used and free disk space
271 statistics. (Contributed by Giampaolo Rodolà in :issue:`12442`)
272 * :func:`~shutil.chown`: allows one to change user and/or group of the given
273 path also specifying the user/group names and not only their numeric
274 ids. (Contributed by Sandro Tosi in :issue:`12191`)
Giampaolo Rodola'096dcb12011-06-27 11:17:51 +0200275
276
Giampaolo Rodolà3108f982011-02-24 20:59:48 +0000277Optimizations
278=============
279
280Major performance enhancements have been added:
281
282* Stub
283
284
285Build and C API Changes
286=======================
287
288Changes to Python's build process and to the C API include:
289
290* Stub
291
292
Georg Brandl0cd25c92011-04-29 13:45:54 +0200293Unsupported Operating Systems
Victor Stinnerb90db4c2011-04-26 22:48:24 +0200294=============================
295
Brian Curtin49a40cd2011-05-02 22:30:06 -0500296OS/2 and VMS are no longer supported due to the lack of a maintainer.
297
298Windows 2000 and Windows platforms which set ``COMSPEC`` to ``command.com``
299are no longer supported due to maintenance burden.
Victor Stinnerb90db4c2011-04-26 22:48:24 +0200300
301
Giampaolo Rodolà3108f982011-02-24 20:59:48 +0000302Porting to Python 3.3
303=====================
304
305This section lists previously described changes and other bugfixes
306that may require changes to your code:
307
Victor Stinnerff3d9392011-08-20 23:39:26 +0200308* Issue #12326: On Linux, sys.platform doesn't contain the major version
309 anymore. It is now always 'linux', instead of 'linux2' or 'linux3' depending
310 on the Linux version used to build Python. Replace sys.platform == 'linux2'
311 with sys.platform.startswith('linux'), or directly sys.platform == 'linux' if
312 you don't need to support older Python versions.
Éric Araujoc09fca62011-03-23 02:06:24 +0100313
314.. Issue #11591: When :program:`python` was started with :option:`-S`,
315 ``import site`` will not add site-specific paths to the module search
316 paths. In previous versions, it did. See changeset for doc changes in
317 various files. Contributed by Carl Meyer with editions by Éric Araujo.
Éric Araujobe3bd572011-03-26 01:55:15 +0100318
319.. Issue #10998: -Q command-line flags are related artifacts have been
320 removed. Code checking sys.flags.division_warning will need updating.
321 Contributed by Éric Araujo.