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| author | Benjamin Peterson <benjamin@python.org> | 2010-06-27 22:32:30 (GMT) |
|---|---|---|
| committer | Benjamin Peterson <benjamin@python.org> | 2010-06-27 22:32:30 (GMT) |
| commit | d7c3ed54ef8ee248958ab5626465c70b9953f9de (patch) | |
| tree | a1a111c5579bbe3a3e8f1188b8bbae8c3e28079c /Doc/whatsnew/2.7.rst | |
| parent | 30b7a90033b8a43c6b634359a02afe17af52993f (diff) | |
| download | cpython-d7c3ed54ef8ee248958ab5626465c70b9953f9de.zip cpython-d7c3ed54ef8ee248958ab5626465c70b9953f9de.tar.gz cpython-d7c3ed54ef8ee248958ab5626465c70b9953f9de.tar.bz2 | |
Merged revisions 80605-80609,80642-80646,80651-80652,80674,80684-80686,80748,80852,80854,80870,80872-80873,80907,80915-80916,80951-80952,80976-80977,80985,81038-81040,81042,81053,81070,81104-81105,81114,81125,81245,81285,81402,81463,81516,81562-81563,81567,81593,81635,81680-81681,81684,81801,81888,81931-81933,81939-81942,81963,81984,81991,82120,82188,82264-82267 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
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r80605 | andrew.kuchling | 2010-04-28 19:22:16 -0500 (Wed, 28 Apr 2010) | 1 line
Add various items
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r80606 | andrew.kuchling | 2010-04-28 20:44:30 -0500 (Wed, 28 Apr 2010) | 6 lines
Fix doubled 'the'.
Markup fixes to use :exc:, :option: in a few places.
(Glitch: unittest.main's -c ends up a link to the Python
interpreter's -c option. Should we skip using :option: for that
switch, or disable the auto-linking somehow?)
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r80607 | andrew.kuchling | 2010-04-28 20:45:41 -0500 (Wed, 28 Apr 2010) | 1 line
Add various unittest items
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r80608 | benjamin.peterson | 2010-04-28 22:18:05 -0500 (Wed, 28 Apr 2010) | 1 line
update pypy description
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r80609 | benjamin.peterson | 2010-04-28 22:30:59 -0500 (Wed, 28 Apr 2010) | 1 line
update pypy url
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r80642 | andrew.kuchling | 2010-04-29 19:49:09 -0500 (Thu, 29 Apr 2010) | 1 line
Always add space after RFC; reword paragraph
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r80643 | andrew.kuchling | 2010-04-29 19:52:31 -0500 (Thu, 29 Apr 2010) | 6 lines
Reword paragraph to make its meaning clearer.
Antoine Pitrou: is my version of the paragraph still correct?
R. David Murray: is this more understandable than the previous version?
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r80644 | andrew.kuchling | 2010-04-29 20:02:15 -0500 (Thu, 29 Apr 2010) | 1 line
Fix typos
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r80645 | andrew.kuchling | 2010-04-29 20:32:47 -0500 (Thu, 29 Apr 2010) | 1 line
Markup fix; clarify by adding 'in that order'
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r80646 | andrew.kuchling | 2010-04-29 20:33:40 -0500 (Thu, 29 Apr 2010) | 1 line
Add various items; rearrange unittest section a bit
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r80651 | andrew.kuchling | 2010-04-30 08:46:55 -0500 (Fri, 30 Apr 2010) | 1 line
Minor grammar re-wording
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r80652 | andrew.kuchling | 2010-04-30 08:47:34 -0500 (Fri, 30 Apr 2010) | 1 line
Add item
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r80674 | andrew.kuchling | 2010-04-30 20:19:16 -0500 (Fri, 30 Apr 2010) | 1 line
Add various items
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r80684 | andrew.kuchling | 2010-05-01 07:05:52 -0500 (Sat, 01 May 2010) | 1 line
Minor grammar fix
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r80685 | andrew.kuchling | 2010-05-01 07:06:51 -0500 (Sat, 01 May 2010) | 1 line
Describe memoryview
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r80686 | antoine.pitrou | 2010-05-01 07:16:39 -0500 (Sat, 01 May 2010) | 4 lines
Fix attribution. Travis didn't do much and he did a bad work.
(yes, this is a sensitive subject, sorry)
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r80748 | andrew.kuchling | 2010-05-03 20:24:22 -0500 (Mon, 03 May 2010) | 1 line
Add some more items; the urlparse change is added twice
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r80852 | andrew.kuchling | 2010-05-05 20:09:47 -0500 (Wed, 05 May 2010) | 1 line
Reword paragraph; fix filename, which should be pyconfig.h
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r80854 | andrew.kuchling | 2010-05-05 20:10:56 -0500 (Wed, 05 May 2010) | 1 line
Add various items
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r80870 | andrew.kuchling | 2010-05-06 09:14:09 -0500 (Thu, 06 May 2010) | 1 line
Describe ElementTree 1.3; rearrange new-module sections; describe dict views as sets; small edits and items
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r80872 | andrew.kuchling | 2010-05-06 12:21:59 -0500 (Thu, 06 May 2010) | 1 line
Add 2 items; record ideas for two initial sections; clarify wording
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r80873 | andrew.kuchling | 2010-05-06 12:27:57 -0500 (Thu, 06 May 2010) | 1 line
Change section title; point to unittest2
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r80907 | andrew.kuchling | 2010-05-06 20:45:14 -0500 (Thu, 06 May 2010) | 1 line
Add a new section on the development plan; add an item
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r80915 | antoine.pitrou | 2010-05-07 05:15:51 -0500 (Fri, 07 May 2010) | 3 lines
Fix some markup and a class name. Also, wrap a long line.
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r80916 | andrew.kuchling | 2010-05-07 06:30:47 -0500 (Fri, 07 May 2010) | 1 line
Re-word text
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r80951 | andrew.kuchling | 2010-05-07 20:15:26 -0500 (Fri, 07 May 2010) | 1 line
Add two items
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r80952 | andrew.kuchling | 2010-05-07 20:35:55 -0500 (Fri, 07 May 2010) | 1 line
Get accents correct
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r80976 | andrew.kuchling | 2010-05-08 08:28:03 -0500 (Sat, 08 May 2010) | 1 line
Add logging.dictConfig example; give up on writing a Ttk example
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r80977 | andrew.kuchling | 2010-05-08 08:29:46 -0500 (Sat, 08 May 2010) | 1 line
Markup fixes
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r80985 | andrew.kuchling | 2010-05-08 10:39:46 -0500 (Sat, 08 May 2010) | 7 lines
Write summary of the 2.7 release; rewrite the future section some more;
mention PYTHONWARNINGS env. var; tweak some examples for readability.
And with this commit, the "What's New" is done... except for a
complete read-through to polish the text, and fixing any reported errors,
but those tasks can easily wait until after beta2.
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r81038 | benjamin.peterson | 2010-05-09 16:09:40 -0500 (Sun, 09 May 2010) | 1 line
finish clause
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r81039 | andrew.kuchling | 2010-05-10 09:18:27 -0500 (Mon, 10 May 2010) | 1 line
Markup fix; re-word a sentence
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r81040 | andrew.kuchling | 2010-05-10 09:20:12 -0500 (Mon, 10 May 2010) | 1 line
Use title case
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r81042 | andrew.kuchling | 2010-05-10 10:03:35 -0500 (Mon, 10 May 2010) | 1 line
Link to unittest2 article
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r81053 | florent.xicluna | 2010-05-10 14:59:22 -0500 (Mon, 10 May 2010) | 2 lines
Add a link on maketrans().
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r81070 | andrew.kuchling | 2010-05-10 18:13:41 -0500 (Mon, 10 May 2010) | 1 line
Fix typo
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r81104 | andrew.kuchling | 2010-05-11 19:38:44 -0500 (Tue, 11 May 2010) | 1 line
Revision pass: lots of edits, typo fixes, rearrangements
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r81105 | andrew.kuchling | 2010-05-11 19:40:47 -0500 (Tue, 11 May 2010) | 1 line
Let's call this done
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r81114 | andrew.kuchling | 2010-05-12 08:56:07 -0500 (Wed, 12 May 2010) | 1 line
Grammar fix
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r81125 | andrew.kuchling | 2010-05-12 13:56:48 -0500 (Wed, 12 May 2010) | 1 line
#8696: add documentation for logging.config.dictConfig (PEP 391)
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r81245 | andrew.kuchling | 2010-05-16 18:31:16 -0500 (Sun, 16 May 2010) | 1 line
Add cross-reference to later section
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r81285 | vinay.sajip | 2010-05-18 03:16:27 -0500 (Tue, 18 May 2010) | 1 line
Fixed minor typo in ReST markup.
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r81402 | vinay.sajip | 2010-05-21 12:41:34 -0500 (Fri, 21 May 2010) | 1 line
Updated logging documentation with more dictConfig information.
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r81463 | georg.brandl | 2010-05-22 03:17:23 -0500 (Sat, 22 May 2010) | 1 line
#8785: less confusing description of regex.find*.
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r81516 | andrew.kuchling | 2010-05-25 08:34:08 -0500 (Tue, 25 May 2010) | 1 line
Add three items
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r81562 | andrew.kuchling | 2010-05-27 08:22:53 -0500 (Thu, 27 May 2010) | 1 line
Rewrite wxWidgets section
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r81563 | andrew.kuchling | 2010-05-27 08:30:09 -0500 (Thu, 27 May 2010) | 1 line
Remove top-level 'General Questions' section, pushing up the questions it contains
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r81567 | andrew.kuchling | 2010-05-27 16:29:59 -0500 (Thu, 27 May 2010) | 1 line
Add item
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r81593 | georg.brandl | 2010-05-29 03:46:18 -0500 (Sat, 29 May 2010) | 1 line
#8616: add new turtle demo "nim".
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r81635 | georg.brandl | 2010-06-01 02:25:23 -0500 (Tue, 01 Jun 2010) | 1 line
Put docs for RegexObject.search() before RegexObject.match() to mirror re.search() and re.match() order.
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r81680 | vinay.sajip | 2010-06-03 17:34:42 -0500 (Thu, 03 Jun 2010) | 1 line
Issue #8890: Documentation changed to avoid reference to temporary files.
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r81681 | sean.reifschneider | 2010-06-03 20:51:26 -0500 (Thu, 03 Jun 2010) | 2 lines
Issue8810: Clearing up docstring for tzinfo.utcoffset.
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r81684 | vinay.sajip | 2010-06-04 08:41:02 -0500 (Fri, 04 Jun 2010) | 1 line
Issue #8890: Documentation changed to avoid reference to temporary files - other cases covered.
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r81801 | andrew.kuchling | 2010-06-07 08:38:40 -0500 (Mon, 07 Jun 2010) | 1 line
#8875: Remove duplicated paragraph
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r81888 | andrew.kuchling | 2010-06-10 20:54:58 -0500 (Thu, 10 Jun 2010) | 1 line
Add a few more items
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r81931 | georg.brandl | 2010-06-12 01:26:54 -0500 (Sat, 12 Jun 2010) | 1 line
Fix punctuation.
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r81932 | georg.brandl | 2010-06-12 01:28:58 -0500 (Sat, 12 Jun 2010) | 1 line
Document that an existing directory raises in mkdir().
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r81933 | georg.brandl | 2010-06-12 01:45:33 -0500 (Sat, 12 Jun 2010) | 1 line
Update version in README.
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r81939 | georg.brandl | 2010-06-12 04:45:01 -0500 (Sat, 12 Jun 2010) | 1 line
Use newer toctree syntax.
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r81940 | georg.brandl | 2010-06-12 04:45:28 -0500 (Sat, 12 Jun 2010) | 1 line
Add document on how to build.
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r81941 | georg.brandl | 2010-06-12 04:45:58 -0500 (Sat, 12 Jun 2010) | 1 line
Fix gratuitous indentation.
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r81942 | georg.brandl | 2010-06-12 04:46:03 -0500 (Sat, 12 Jun 2010) | 1 line
Update README.
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r81963 | andrew.kuchling | 2010-06-12 15:00:55 -0500 (Sat, 12 Jun 2010) | 1 line
Grammar fix
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r81984 | georg.brandl | 2010-06-14 10:58:39 -0500 (Mon, 14 Jun 2010) | 1 line
#8993: fix reference.
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r81991 | andrew.kuchling | 2010-06-14 19:38:58 -0500 (Mon, 14 Jun 2010) | 1 line
Add another bunch of items
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r82120 | andrew.kuchling | 2010-06-20 16:45:45 -0500 (Sun, 20 Jun 2010) | 1 line
Note that Python 3.x isn't covered; add forward ref. for UTF-8; note error in 2.5 and up
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r82188 | benjamin.peterson | 2010-06-23 19:02:46 -0500 (Wed, 23 Jun 2010) | 1 line
remove reverted changed
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r82264 | georg.brandl | 2010-06-27 05:47:47 -0500 (Sun, 27 Jun 2010) | 1 line
Confusing punctuation.
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r82265 | georg.brandl | 2010-06-27 05:49:23 -0500 (Sun, 27 Jun 2010) | 1 line
Use designated syntax for optional grammar element.
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r82266 | georg.brandl | 2010-06-27 05:51:44 -0500 (Sun, 27 Jun 2010) | 1 line
Fix URL.
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r82267 | georg.brandl | 2010-06-27 05:55:38 -0500 (Sun, 27 Jun 2010) | 1 line
Two typos.
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Diffstat (limited to 'Doc/whatsnew/2.7.rst')
| -rw-r--r-- | Doc/whatsnew/2.7.rst | 1257 |
1 files changed, 971 insertions, 286 deletions
diff --git a/Doc/whatsnew/2.7.rst b/Doc/whatsnew/2.7.rst index 74563d9..ded7f7e 100644 --- a/Doc/whatsnew/2.7.rst +++ b/Doc/whatsnew/2.7.rst @@ -6,12 +6,11 @@ :Release: |release| :Date: |today| -.. Fix accents on Kristjan Valur Jonsson, Fuerstenau - -.. Big jobs: ElementTree 1.3, pep 391, sysconfig -.. unittest test discovery .. hyperlink all the methods & functions. +.. T_STRING_INPLACE not described in main docs +.. "Format String Syntax" in string.rst could use many more examples. + .. $Id$ Rules for maintenance: @@ -54,20 +53,77 @@ when researching a change. This article explains the new features in Python 2.7. The final -release of 2.7 is currently scheduled for June 2010; the detailed +release of 2.7 is currently scheduled for July 2010; the detailed schedule is described in :pep:`373`. -Python 2.7 is planned to be the last major release in the 2.x series. -Though more major releases have not been absolutely ruled out, the -Python maintainers are planning to focus more on Python 3.x. Despite -that, it's likely that the 2.7 release will have a longer period of -maintenance compared to earlier 2.x versions. - -.. Compare with previous release in 2 - 3 sentences here. - add hyperlink when the documentation becomes available online. +Numeric handling has been improved in many ways, for both +floating-point numbers and for the :class:`Decimal` class. There are +some useful additions to the standard library, such as a greatly +enhanced :mod:`unittest` module, the :mod:`argparse` module for +parsing command-line options, convenient ordered-dictionary and +:class:`Counter` classes in the :mod:`collections` module, and many +other improvements. + +Python 2.7 is planned to be the last of the 2.x releases, so we worked +on making it a good release for the long term. To help with porting +to Python 3, several new features from the Python 3.x series have been +included in 2.7. + +This article doesn't attempt to provide a complete specification of +the new features, but instead provides a convenient overview. For +full details, you should refer to the documentation for Python 2.7 at +http://docs.python.org. If you want to understand the rationale for +the design and implementation, refer to the PEP for a particular new +feature or the issue on http://bugs.python.org in which a change was +discussed. Whenever possible, "What's New in Python" links to the +bug/patch item for each change. .. _whatsnew27-python31: +The Future for Python 2.x +========================= + +Python 2.7 is intended to be the last major release in the 2.x series. +The Python maintainers are planning to focus their future efforts on +the Python 3.x series. + +This means that 2.7 will remain in place for a long time, running +production systems that have not been ported to Python 3.x. +Two consequences of the long-term significance of 2.7 are: + +* It's very likely the 2.7 release will have a longer period of + maintenance compared to earlier 2.x versions. Python 2.7 will + continue to be maintained while the transition to 3.x continues, and + the developers are planning to support Python 2.7 with bug-fix + releases beyond the typical two years. + +* A policy decision was made to silence warnings only of interest to + developers. :exc:`DeprecationWarning` and its + descendants are now ignored unless otherwise requested, preventing + users from seeing warnings triggered by an application. This change + was also made in the branch that will become Python 3.2. (Discussed + on stdlib-sig and carried out in :issue:`7319`.) + + In previous releases, :exc:`DeprecationWarning` messages were + enabled by default, providing Python developers with a clear + indication of where their code may break in a future major version + of Python. + + However, there are increasingly many users of Python-based + applications who are not directly involved in the development of + those applications. :exc:`DeprecationWarning` messages are + irrelevant to such users, making them worry about an application + that's actually working correctly and burdening application developers + with responding to these concerns. + + You can re-enable display of :exc:`DeprecationWarning` messages by + running Python with the :option:`-Wdefault` (short form: + :option:`-Wd`) switch, or by setting the :envvar:`PYTHONWARNINGS` + environment variable to ``"default"`` (or ``"d"``) before running + Python. Python code can also re-enable them + by calling ``warnings.simplefilter('default')``. + + Python 3.1 Features ======================= @@ -78,25 +134,31 @@ for migrating to the 3.x series. A partial list of 3.1 features that were backported to 2.7: -* A version of the :mod:`io` library, rewritten in C for performance. +* The syntax for set literals (``{1,2,3}`` is a mutable set). +* Dictionary and set comprehensions (``{ i: i*2 for i in range(3)}``). +* Multiple context managers in a single :keyword:`with` statement. +* A new version of the :mod:`io` library, rewritten in C for performance. * The ordered-dictionary type described in :ref:`pep-0372`. -* The new format specifier described in :ref:`pep-0378`. +* The new ``","`` format specifier described in :ref:`pep-0378`. * The :class:`memoryview` object. -* A small subset of the :mod:`importlib` module `described below <#importlib-section>`__. +* A small subset of the :mod:`importlib` module, + `described below <#importlib-section>`__. * Float-to-string and string-to-float conversions now round their - results more correctly. And :func:`repr` of a floating-point + results more correctly, and :func:`repr` of a floating-point number *x* returns a result that's guaranteed to round back to the same number when converted back to a string. +* The :ctype:`PyCapsule` type, used to provide a C API for extension modules. * The :cfunc:`PyLong_AsLongAndOverflow` C API function. -One porting change: the :option:`-3` switch now automatically -enables the :option:`-Qwarn` switch that causes warnings -about using classic division with integers and long integers. - Other new Python3-mode warnings include: * :func:`operator.isCallable` and :func:`operator.sequenceIncludes`, - which are not supported in 3.x. + which are not supported in 3.x, now trigger warnings. +* The :option:`-3` switch now automatically + enables the :option:`-Qwarn` switch that causes warnings + about using classic division with integers and long integers. + + .. ======================================================================== .. Large, PEP-level features and changes should be described here. @@ -104,22 +166,22 @@ Other new Python3-mode warnings include: .. _pep-0372: -PEP 372: Adding an ordered dictionary to collections +PEP 372: Adding an Ordered Dictionary to collections ==================================================== Regular Python dictionaries iterate over key/value pairs in arbitrary order. Over the years, a number of authors have written alternative implementations that remember the order that the keys were originally inserted. Based on -the experiences from those implementations, a new -:class:`~collections.OrderedDict` class has been introduced in the -:mod:`collections` module. +the experiences from those implementations, 2.7 introduces a new +:class:`~collections.OrderedDict` class in the :mod:`collections` module. -The :class:`~collections.OrderedDict` API is substantially the same as regular -dictionaries but will iterate over keys and values in a guaranteed order +The :class:`~collections.OrderedDict` API provides the same interface as regular +dictionaries but iterates over keys and values in a guaranteed order depending on when a key was first inserted:: >>> from collections import OrderedDict - >>> d = OrderedDict([('first', 1), ('second', 2), + >>> d = OrderedDict([('first', 1), + ... ('second', 2), ... ('third', 3)]) >>> d.items() [('first', 1), ('second', 2), ('third', 3)] @@ -156,9 +218,11 @@ oldest key is selected:: Comparing two ordered dictionaries checks both the keys and values, and requires that the insertion order was the same:: - >>> od1 = OrderedDict([('first', 1), ('second', 2), + >>> od1 = OrderedDict([('first', 1), + ... ('second', 2), ... ('third', 3)]) - >>> od2 = OrderedDict([('third', 3), ('first', 1), + >>> od2 = OrderedDict([('third', 3), + ... ('first', 1), ... ('second', 2)]) >>> od1 == od2 False @@ -176,17 +240,12 @@ A secondary dictionary maps keys to their corresponding list node, so deletion doesn't have to traverse the entire linked list and therefore remains O(1). -.. XXX check O(1)-ness with Raymond -.. Also check if the 'somenamedtuple' in the collection module should -.. be replaced/removed in order to use -.. :meth:`~collections.namedtuple._asdict()` (see below) - The standard library now supports use of ordered dictionaries in several modules. -* The :mod:`ConfigParser` module uses them by default, letting - configuration files be read, modified, and then written back in their original - order. +* The :mod:`ConfigParser` module uses them by default, meaning that + configuration files can now read, modified, and then written back + in their original order. * The :meth:`~collections.somenamedtuple._asdict()` method for :func:`collections.namedtuple` now returns an ordered dictionary with the @@ -210,7 +269,7 @@ PEP 378: Format Specifier for Thousands Separator ================================================= To make program output more readable, it can be useful to add -separators to large numbers and render them as +separators to large numbers, rendering them as 18,446,744,073,709,551,616 instead of 18446744073709551616. The fully general solution for doing this is the :mod:`locale` module, @@ -237,8 +296,6 @@ separator and the grouping is always into three-digit groups. The comma-formatting mechanism isn't as general as the :mod:`locale` module, but it's easier to use. -.. XXX "Format String Syntax" in string.rst could use many more examples. - .. seealso:: :pep:`378` - Format Specifier for Thousands Separator @@ -248,13 +305,13 @@ PEP 389: The argparse Module for Parsing Command Lines ====================================================== The :mod:`argparse` module for parsing command-line arguments was -added, intended as a more powerful replacement for the +added as a more powerful replacement for the :mod:`optparse` module. This means Python now supports three different modules for parsing command-line arguments: :mod:`getopt`, :mod:`optparse`, and :mod:`argparse`. The :mod:`getopt` module closely resembles the C -:cfunc:`getopt` function, so it remains useful if you're writing a +library's :cfunc:`getopt` function, so it remains useful if you're writing a Python prototype that will eventually be rewritten in C. :mod:`optparse` becomes redundant, but there are no plans to remove it because there are many scripts still using it, and there's no @@ -306,23 +363,28 @@ are automatically added, and produce neatly formatted output:: -o FILE direct output to FILE instead of stdout -C NUM display NUM lines of added context -Similarly to :mod:`optparse`, the command-line switches and arguments +As with :mod:`optparse`, the command-line switches and arguments are returned as an object with attributes named by the *dest* parameters:: -> ./python.exe argparse-example.py -v - {'output': None, 'is_verbose': True, 'context': 0, 'inputs': []} + {'output': None, + 'is_verbose': True, + 'context': 0, + 'inputs': []} -> ./python.exe argparse-example.py -v -o /tmp/output -C 4 file1 file2 - {'output': '/tmp/output', 'is_verbose': True, 'context': 4, + {'output': '/tmp/output', + 'is_verbose': True, + 'context': 4, 'inputs': ['file1', 'file2']} :mod:`argparse` has much fancier validation than :mod:`optparse`; you can specify an exact number of arguments as an integer, 0 or more arguments by passing ``'*'``, 1 or more by passing ``'+'``, or an optional argument with ``'?'``. A top-level parser can contain -sub-parsers, so you can define subcommands that have different sets of +sub-parsers to define subcommands that have different sets of switches, as in ``svn commit``, ``svn checkout``, etc. You can -specify an argument type as :class:`~argparse.FileType`, which will +specify an argument's type as :class:`~argparse.FileType`, which will automatically open files for you and understands that ``'-'`` means standard input or output. @@ -331,6 +393,8 @@ standard input or output. `argparse module documentation <http://docs.python.org/dev/library/argparse.html>`__ `Upgrading optparse code to use argparse <http://docs.python.org/dev/library/argparse.html#upgrading-optparse-code>`__ + Part of the Python documentation, describing how to convert + code that uses :mod:`optparse`. :pep:`389` - argparse - New Command Line Parsing Module PEP written and implemented by Steven Bethard. @@ -338,34 +402,88 @@ standard input or output. PEP 391: Dictionary-Based Configuration For Logging ==================================================== -.. not documented in library reference yet. +.. XXX not documented in library reference yet; add link here once it's added. -The :mod:`logging` module is very flexible; an application can define +The :mod:`logging` module is very flexible; applications can define a tree of logging subsystems, and each logger in this tree can filter out certain messages, format them differently, and direct messages to a varying number of handlers. All this flexibility can require a lot of configuration. You can write Python statements to create objects and set their properties, -but a complex set-up would require verbose but boring code. +but a complex set-up requires verbose but boring code. :mod:`logging` also supports a :func:`~logging.config.fileConfig` function that parses a file, but the file format doesn't support configuring filters, and it's messier to generate programmatically. Python 2.7 adds a :func:`~logging.config.dictConfig` function that -uses a dictionary, and there are many ways to produce a dictionary -from different sources. You can construct one with code, of course. -Python's standard library now includes a JSON parser, so you could -parse a file containing JSON, or you could use a YAML parsing library -if one is installed. +uses a dictionary to configure logging. There are many ways to +produce a dictionary from different sources: construct one with code; +parse a file containing JSON; or use a YAML parsing library if one is +installed. -XXX describe an example. +The following example configures two loggers, the root logger and a +logger named "network". Messages sent to the root logger will be +sent to the system log using the syslog protocol, and messages +to the "network" logger will be written to a :file:`network.log` file +that will be rotated once the log reaches 1Mb. -Two smaller enhancements to the logging module are: +:: + + import logging + import logging.config + + configdict = { + 'version': 1, # Configuration schema in use; must be 1 for now + 'formatters': { + 'standard': { + 'format': ('%(asctime)s %(name)-15s ' + '%(levelname)-8s %(message)s')}}, + + 'handlers': {'netlog': {'backupCount': 10, + 'class': 'logging.handlers.RotatingFileHandler', + 'filename': '/logs/network.log', + 'formatter': 'standard', + 'level': 'INFO', + 'maxBytes': 1024*1024}, + 'syslog': {'class': 'logging.handlers.SysLogHandler', + 'formatter': 'standard', + 'level': 'ERROR'}}, + + # Specify all the subordinate loggers + 'loggers': { + 'network': { + 'handlers': ['netlog'] + } + }, + # Specify properties of the root logger + 'root': { + 'handlers': ['syslog'] + }, + } + + # Set up configuration + logging.config.dictConfig(configdict) + + # As an example, log two error messages + logger = logging.getLogger('/') + logger.error('Database not found') + + netlogger = logging.getLogger('network') + netlogger.error('Connection failed') + +Three smaller enhancements to the :mod:`logging` module, all +implemented by Vinay Sajip, are: .. rev79293 -* :class:`Logger` instances gained a :meth:`getChild` that retrieves a +* The :class:`~logging.handlers.SysLogHandler` class now supports + syslogging over TCP. The constructor has a *socktype* parameter + giving the type of socket to use, either :const:`socket.SOCK_DGRAM` + for UDP or :const:`socket.SOCK_STREAM` for TCP. The default + protocol remains UDP. + +* :class:`Logger` instances gained a :meth:`getChild` method that retrieves a descendant logger using a relative path. For example, once you retrieve a logger by doing ``log = getLogger('app')``, calling ``log.getChild('network.listen')`` is equivalent to @@ -387,12 +505,10 @@ The dictionary methods :meth:`keys`, :meth:`values`, and :meth:`items` are different in Python 3.x. They return an object called a :dfn:`view` instead of a fully materialized list. -.. Views can be iterated over, but they also behave like sets. XXX not working. - It's not possible to change the return values of :meth:`keys`, :meth:`values`, and :meth:`items` in Python 2.7 because too much code would break. Instead the 3.x versions were added under the new names -of :meth:`viewkeys`, :meth:`viewvalues`, and :meth:`viewitems`. +:meth:`viewkeys`, :meth:`viewvalues`, and :meth:`viewitems`. :: @@ -402,6 +518,17 @@ of :meth:`viewkeys`, :meth:`viewvalues`, and :meth:`viewitems`. >>> d.viewkeys() dict_keys([0, 130, 10, 140, 20, 150, 30, ..., 250]) +Views can be iterated over, but the key and item views also behave +like sets. The ``&`` operator performs intersection, and ``|`` +performs a union:: + + >>> d1 = dict((i*10, chr(65+i)) for i in range(26)) + >>> d2 = dict((i**.5, i) for i in range(1000)) + >>> d1.viewkeys() & d2.viewkeys() + set([0.0, 10.0, 20.0, 30.0]) + >>> d1.viewkeys() | range(0, 30) + set([0, 1, 130, 3, 4, 5, 6, ..., 120, 250]) + The view keeps track of the dictionary and its contents change as the dictionary is modified:: @@ -433,6 +560,58 @@ converter will change them to the standard :meth:`keys`, Backported to 2.7 by Alexandre Vassalotti; :issue:`1967`. +PEP 3137: The memoryview Object +==================================================== + +The :class:`memoryview` object provides a view of another object's +memory content that matches the :class:`bytes` type's interface. + + >>> import string + >>> m = memoryview(string.letters) + >>> m + <memory at 0x37f850> + >>> len(m) # Returns length of underlying object + 52 + >>> m[0], m[25], m[26] # Indexing returns one byte + ('a', 'z', 'A') + >>> m2 = m[0:26] # Slicing returns another memoryview + >>> m2 + <memory at 0x37f080> + +The content of the view can be converted to a string of bytes or +a list of integers: + + >>> m2.tobytes() + 'abcdefghijklmnopqrstuvwxyz' + >>> m2.tolist() + [97, 98, 99, 100, 101, 102, 103, ... 121, 122] + >>> + +:class:`memoryview` objects allow modifying the underlying object if +it's a mutable object. + + >>> m2[0] = 75 + Traceback (most recent call last): + File "<stdin>", line 1, in <module> + TypeError: cannot modify read-only memory + >>> b = bytearray(string.letters) # Creating a mutable object + >>> b + bytearray(b'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ') + >>> mb = memoryview(b) + >>> mb[0] = '*' # Assign to view, changing the bytearray. + >>> b[0:5] # The bytearray has been changed. + bytearray(b'*bcde') + >>> + +.. seealso:: + + :pep:`3137` - Immutable Bytes and Mutable Buffer + PEP written by Guido van Rossum. + Implemented by Travis Oliphant, Antoine Pitrou and others. + Backported to 2.7 by Antoine Pitrou; :issue:`2396`. + + + Other Language Changes ====================== @@ -458,9 +637,9 @@ Some smaller changes made to the core Python language are: 3.x, generalizing list/generator comprehensions to use the literal syntax for sets and dictionaries. - >>> {x:x*x for x in range(6)} + >>> {x: x*x for x in range(6)} {0: 0, 1: 1, 2: 4, 3: 9, 4: 16, 5: 25} - >>> {'a'*x for x in range(6)} + >>> {('a'*x) for x in range(6)} set(['', 'a', 'aa', 'aaa', 'aaaa', 'aaaaa']) Backported by Alexandre Vassalotti; :issue:`2333`. @@ -490,8 +669,8 @@ Some smaller changes made to the core Python language are: in many different places: :func:`str` on floats and complex numbers; the :class:`float` and :class:`complex` constructors; - numeric formatting; serialization and - deserialization of floats and complex numbers using the + numeric formatting; serializing and + deserializing floats and complex numbers using the :mod:`marshal`, :mod:`pickle` and :mod:`json` modules; parsing of float and imaginary literals in Python code; @@ -506,7 +685,7 @@ Some smaller changes made to the core Python language are: .. maybe add an example? The rounding library responsible for this improvement works on - Windows, and on Unix platforms using the gcc, icc, or suncc + Windows and on Unix platforms using the gcc, icc, or suncc compilers. There may be a small number of platforms where correct operation of this code cannot be guaranteed, so the code is not used on such systems. You can find out which code is being used @@ -516,6 +695,37 @@ Some smaller changes made to the core Python language are: Implemented by Eric Smith and Mark Dickinson, using David Gay's :file:`dtoa.c` library; :issue:`7117`. +* Conversions from long integers and regular integers to floating + point now round differently, returning the floating-point number + closest to the number. This doesn't matter for small integers that + can be converted exactly, but for large numbers that will + unavoidably lose precision, Python 2.7 now approximates more + closely. For example, Python 2.6 computed the following:: + + >>> n = 295147905179352891391 + >>> float(n) + 2.9514790517935283e+20 + >>> n - long(float(n)) + 65535L + + Python 2.7's floating-point result is larger, but much closer to the + true value:: + + >>> n = 295147905179352891391 + >>> float(n) + 2.9514790517935289e+20 + >>> n - long(float(n)) + -1L + + (Implemented by Mark Dickinson; :issue:`3166`.) + + Integer division is also more accurate in its rounding behaviours. (Also + implemented by Mark Dickinson; :issue:`1811`.) + +* Implicit coercion for complex numbers has been removed; the interpreter + will no longer ever attempt to call a :meth:`__coerce__` method on complex + objects. (Removed by Meador Inge and Mark Dickinson; :issue:`5211`.) + * The :meth:`str.format` method now supports automatic numbering of the replacement fields. This makes using :meth:`str.format` more closely resemble using ``%s`` formatting:: @@ -543,6 +753,16 @@ Some smaller changes made to the core Python language are: so it will now produce 'INF' and 'NAN'. (Contributed by Eric Smith; :issue:`3382`.) + A low-level change: the :meth:`object.__format__` method now triggers + a :exc:`PendingDeprecationWarning` if it's passed a format string, + because the :meth:`__format__` method for :class:`object` converts + the object to a string representation and formats that. Previously + the method silently applied the format string to the string + representation, but that could hide mistakes in Python code. If + you're supplying formatting information such as an alignment or + precision, presumably you're expecting the formatting to be applied + in some object-specific way. (Fixed by Eric Smith; :issue:`7994`.) + * The :func:`int` and :func:`long` types gained a ``bit_length`` method that returns the number of bits necessary to represent its argument in binary:: @@ -560,32 +780,11 @@ Some smaller changes made to the core Python language are: (Contributed by Fredrik Johansson and Victor Stinner; :issue:`3439`.) -* Conversions from long integers and regular integers to floating - point now round differently, returning the floating-point number - closest to the number. This doesn't matter for small integers that - can be converted exactly, but for large numbers that will - unavoidably lose precision, Python 2.7 now approximates more - closely. For example, Python 2.6 computed the following:: - - >>> n = 295147905179352891391 - >>> float(n) - 2.9514790517935283e+20 - >>> n - long(float(n)) - 65535L - - Python 2.7's floating-point result is larger, but much closer to the - true value:: - - >>> n = 295147905179352891391 - >>> float(n) - 2.9514790517935289e+20 - >>> n - long(float(n)) - -1L - - (Implemented by Mark Dickinson; :issue:`3166`.) - - Integer division is also more accurate in its rounding behaviours. (Also - implemented by Mark Dickinson; :issue:`1811`.) +* The :keyword:`import` statement will no longer try a relative import + if an absolute import (e.g. ``from .os import sep``) fails. This + fixes a bug, but could possibly break certain :keyword:`import` + statements that were only working by accident. (Fixed by Meador Inge; + :issue:`7902`.) * It's now possible for a subclass of the built-in :class:`unicode` type to override the :meth:`__unicode__` method. (Implemented by @@ -603,9 +802,15 @@ Some smaller changes made to the core Python language are: (Contributed by Amaury Forgeot d'Arc, after a suggestion by George Sakkis; :issue:`5982`.) -* A new encoding named "cp720", used primarily for Arabic text, is now - supported. (Contributed by Alexander Belchenko and Amaury Forgeot - d'Arc; :issue:`1616979`.) +* When a restricted set of attributes were set using ``__slots__``, + deleting an unset attribute would not raise :exc:`AttributeError` + as you would expect. Fixed by Benjamin Peterson; :issue:`7604`.) + +* Two new encodings are now supported: "cp720", used primarily for + Arabic text; and "cp858", a variant of CP 850 that adds the euro + symbol. (CP720 contributed by Alexander Belchenko and Amaury + Forgeot d'Arc in :issue:`1616979`; CP858 contributed by Tim Hatch in + :issue:`8016`.) * The :class:`file` object will now set the :attr:`filename` attribute on the :exc:`IOError` exception when trying to open a directory @@ -615,7 +820,7 @@ Some smaller changes made to the core Python language are: (fixed by Stefan Krah; :issue:`5677`). * The Python tokenizer now translates line endings itself, so the - :func:`compile` built-in function can now accept code using any + :func:`compile` built-in function now accepts code using any line-ending convention. Additionally, it no longer requires that the code end in a newline. @@ -648,12 +853,18 @@ used with the :option:`-W` switch, separated by commas. For example, the following setting will print warnings every time they occur, but turn warnings from the :mod:`Cookie` module into an error. (The exact syntax for setting an environment variable varies -across operating systems and shells, so it may be different for you.) +across operating systems and shells.) :: export PYTHONWARNINGS=all,error:::Cookie:0 +When running a module using the interpreter's :option:`-m` switch, +``sys.argv[0]`` will now be set to the string ``'-m'`` while the +module is being located, while executing the :file:`__init__.py` files +for any parent packages of the module to be executed. +(Suggested by Michael Foord; implemented by Nick Coghlan; +:issue:`8202`.) .. ====================================================================== @@ -678,7 +889,7 @@ Several performance enhancements have been added: any of them. This would previously take quadratic time for garbage collection, but now the number of full garbage collections is reduced as the number of objects on the heap grows. - The new logic is to only perform a full garbage collection pass when + The new logic only performs a full garbage collection pass when the middle generation has been collected 10 times and when the number of survivor objects from the middle generation exceeds 10% of the number of objects in the oldest generation. (Suggested by Martin @@ -788,11 +999,11 @@ changes, or look through the Subversion logs for all the details. The new version features better Python 3.x compatibility, various bug fixes, and adds several new BerkeleyDB flags and methods. (Updated by Jesús Cea Avión; :issue:`8156`. The pybsddb - changelog can be browsed at http://hg.jcea.es/pybsddb/file/tip/ChangeLog.) + changelog can be read at http://hg.jcea.es/pybsddb/file/tip/ChangeLog.) * The :mod:`bz2` module's :class:`~bz2.BZ2File` now supports the context - management protocol, so you can write ``with bz2.BZ2File(...) as f: ...``. - (Contributed by Hagen Fuerstenau; :issue:`3860`.) + management protocol, so you can write ``with bz2.BZ2File(...) as f:``. + (Contributed by Hagen Fürstenau; :issue:`3860`.) * New class: the :class:`~collections.Counter` class in the :mod:`collections` module is useful for tallying data. :class:`~collections.Counter` instances @@ -816,7 +1027,7 @@ changes, or look through the Subversion logs for all the details. >>> c['z'] 0 - There are three additional :class:`~collections.Counter` methods: + There are three additional :class:`~collections.Counter` methods. :meth:`~collections.Counter.most_common` returns the N most common elements and their counts. :meth:`~collections.Counter.elements` returns an iterator over the contained elements, repeating each @@ -843,12 +1054,20 @@ changes, or look through the Subversion logs for all the details. .. revision 79660 - The new :class:`~collections.OrderedDict` class is described in the earlier + New class: :class:`~collections.OrderedDict` is described in the earlier section :ref:`pep-0372`. + New method: The :class:`~collections.deque` data type now has a + :meth:`~collections.deque.count` method that returns the number of + contained elements equal to the supplied argument *x*, and a + :meth:`~collections.deque.reverse` method that reverses the elements + of the deque in-place. :class:`deque` also exposes its maximum + length as the read-only :attr:`~collections.deque.maxlen` attribute. + (Both features added by Raymond Hettinger.) + The :class:`~collections.namedtuple` class now has an optional *rename* parameter. If *rename* is true, field names that are invalid because they've - been repeated or that aren't legal Python identifiers will be + been repeated or aren't legal Python identifiers will be renamed to legal names that are derived from the field's position within the list of fields: @@ -859,13 +1078,43 @@ changes, or look through the Subversion logs for all the details. (Added by Raymond Hettinger; :issue:`1818`.) - The :class:`~collections.deque` data type now has a - :meth:`~collections.deque.count` method that returns the number of - contained elements equal to the supplied argument *x*, and a - :meth:`~collections.deque.reverse` method that reverses the elements - of the deque in-place. :class:`deque` also exposes its maximum - length as the read-only :attr:`~collections.deque.maxlen` attribute. - (Both features added by Raymond Hettinger.) + Finally, the :class:`~collections.Mapping` abstract base class now + raises a :exc:`NotImplemented` exception if a mapping is compared to + another type that isn't a :class:`Mapping`. + (Fixed by Daniel Stutzbach; :issue:`8729`.) + +* Constructors for the parsing classes in the :mod:`ConfigParser` module now + take a *allow_no_value* parameter, defaulting to false; if true, + options without values will be allowed. For example:: + + >>> import ConfigParser, StringIO + >>> sample_config = """ + ... [mysqld] + ... user = mysql + ... pid-file = /var/run/mysqld/mysqld.pid + ... skip-bdb + ... """ + >>> config = ConfigParser.RawConfigParser(allow_no_value=True) + >>> config.readfp(StringIO.StringIO(sample_config)) + >>> config.get('mysqld', 'user') + 'mysql' + >>> print config.get('mysqld', 'skip-bdb') + None + >>> print config.get('mysqld', 'unknown') + Traceback (most recent call last): + ... + NoOptionError: No option 'unknown' in section: 'mysqld' + + (Contributed by Mats Kindahl; :issue:`7005`.) + +* Deprecated function: :func:`contextlib.nested`, which allows + handling more than one context manager with a single :keyword:`with` + statement, has been deprecated, because the :keyword:`with` statement + now supports multiple context managers. + +* The :mod:`cookielib` module now ignores cookies that have an invalid + version field, one that doesn't contain an integer value. (Fixed by + John J. Lee; :issue:`3924`.) * The :mod:`copy` module's :func:`~copy.deepcopy` function will now correctly copy bound instance methods. (Implemented by @@ -885,7 +1134,7 @@ changes, or look through the Subversion logs for all the details. * New method: the :class:`~decimal.Decimal` class gained a :meth:`~decimal.Decimal.from_float` class method that performs an exact conversion of a floating-point number to a :class:`~decimal.Decimal`. - Note that this is an **exact** conversion that strives for the + This exact conversion strives for the closest decimal approximation to the floating-point representation's value; the resulting decimal value will therefore still include the inaccuracy, if any. @@ -893,27 +1142,57 @@ changes, or look through the Subversion logs for all the details. ``Decimal('0.1000000000000000055511151231257827021181583404541015625')``. (Implemented by Raymond Hettinger; :issue:`4796`.) - Most of the methods of the :class:`~decimal.Context` class now accept integers - as well as :class:`~decimal.Decimal` instances; the only exceptions are the - :meth:`~decimal.Context.canonical` and :meth:`~decimal.Context.is_canonical` - methods. (Patch by Juan José Conti; :issue:`7633`.) + Comparing instances of :class:`Decimal` with floating-point + numbers now produces sensible results based on the numeric values + of the operands. Previously such comparisons would fall back to + Python's default rules for comparing objects, which produced arbitrary + results based on their type. Note that you still cannot combine + :class:`Decimal` and floating-point in other operations such as addition, + since you should be explicitly choosing how to convert between float and + :class:`Decimal`. + (Fixed by Mark Dickinson; :issue:`2531`.) The constructor for :class:`~decimal.Decimal` now accepts floating-point numbers (added by Raymond Hettinger; :issue:`8257`) and non-European Unicode characters such as Arabic-Indic digits (contributed by Mark Dickinson; :issue:`6595`). + Most of the methods of the :class:`~decimal.Context` class now accept integers + as well as :class:`~decimal.Decimal` instances; the only exceptions are the + :meth:`~decimal.Context.canonical` and :meth:`~decimal.Context.is_canonical` + methods. (Patch by Juan José Conti; :issue:`7633`.) + When using :class:`~decimal.Decimal` instances with a string's :meth:`~str.format` method, the default alignment was previously - left-alignment. This has been changed to right-alignment, which seems + left-alignment. This has been changed to right-alignment, which is more sensible for numeric types. (Changed by Mark Dickinson; :issue:`6857`.) + Comparisons involving a signaling NaN value (or ``sNAN``) now signal + :const:`InvalidOperation` instead of silently returning a true or + false value depending on the comparison operator. Quiet NaN values + (or ``NaN``) are now hashable. (Fixed by Mark Dickinson; + :issue:`7279`.) + * The :mod:`difflib` module now produces output that is more - compatible with modern :command:`diff`/:command:`patch` tools thanks - to two changes: 1) the header giving the filename now uses a tab - character instead of spaces as a separator, and 2) the date format - used is now ISO-8601 style, ``2005-01-26 23:30:50``. (Fixed by - Anatoly Techtonik; :issue:`7585`.) + compatible with modern :command:`diff`/:command:`patch` tools + through one small change, using a tab character instead of spaces as + a separator in the header giving the filename. (Fixed by Anatoly + Techtonik; :issue:`7585`.) + +* The Distutils ``sdist`` command now always regenerates the + :file:`MANIFEST` file, since even if the :file:`MANIFEST.in` or + :file:`setup.py` files haven't been modified, the user might have + created some new files that should be included. + (Fixed by Tarek Ziadé; :issue:`8688`.) + +* The :mod:`doctest` module's :const:`IGNORE_EXCEPTION_DETAIL` flag + will now ignore the name of the module containing the exception + being tested. (Patch by Lennart Regebro; :issue:`7490`.) + +* The :mod:`email` module's :class:`~email.message.Message` class will + now accept a Unicode-valued payload, automatically converting the + payload to the encoding specified by :attr:`output_charset`. + (Added by R. David Murray; :issue:`1368247`.) * The :class:`~fractions.Fraction` class now accepts a single float or :class:`~decimal.Decimal` instance, or two rational numbers, as @@ -921,17 +1200,18 @@ changes, or look through the Subversion logs for all the details. rationals added in :issue:`5812`, and float/decimal in :issue:`8294`.) - An oversight was fixed, making the :class:`Fraction` match the other - numeric types; ordering comparisons (``<``, ``<=``, ``>``, ``>=``) between + Ordering comparisons (``<``, ``<=``, ``>``, ``>=``) between fractions and complex numbers now raise a :exc:`TypeError`. + This fixes an oversight, making the :class:`Fraction` match the other + numeric types. .. revision 79455 -* New class: a new :class:`~ftplib.FTP_TLS` class in +* New class: :class:`~ftplib.FTP_TLS` in the :mod:`ftplib` module provides secure FTP connections using TLS encapsulation of authentication as well as subsequent control and data transfers. - (Contributed by Giampaolo Rodola', :issue:`2054`.) + (Contributed by Giampaolo Rodola; :issue:`2054`.) The :meth:`~ftplib.FTP.storbinary` method for binary uploads can now restart uploads thanks to an added *rest* parameter (patch by Pablo Mouzo; @@ -957,8 +1237,8 @@ changes, or look through the Subversion logs for all the details. otherwise. (Contributed by Antoine Pitrou; :issue:`4688`.) * The :mod:`gzip` module's :class:`~gzip.GzipFile` now supports the context - management protocol, so you can write ``with gzip.GzipFile(...) as f: ...`` - (contributed by Hagen Fuerstenau; :issue:`3860`), and it now implements + management protocol, so you can write ``with gzip.GzipFile(...) as f:`` + (contributed by Hagen Fürstenau; :issue:`3860`), and it now implements the :class:`io.BufferedIOBase` ABC, so you can wrap it with :class:`io.BufferedReader` for faster processing (contributed by Nir Aides; :issue:`7471`). @@ -973,18 +1253,25 @@ changes, or look through the Subversion logs for all the details. * New attribute: the :mod:`hashlib` module now has an :attr:`~hashlib.hashlib.algorithms` attribute containing a tuple naming the supported algorithms. In Python 2.7, ``hashlib.algorithms`` contains - ``('md5', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512')`` + ``('md5', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512')``. (Contributed by Carl Chenet; :issue:`7418`.) * The default :class:`~httplib.HTTPResponse` class used by the :mod:`httplib` module now supports buffering, resulting in much faster reading of HTTP responses. - (Contributed by Kristjan Valur Jonsson; :issue:`4879`.) + (Contributed by Kristján Valur Jónsson; :issue:`4879`.) The :class:`~httplib.HTTPConnection` and :class:`~httplib.HTTPSConnection` classes now support a *source_address* parameter, a ``(host, port)`` 2-tuple giving the source address that will be used for the connection. (Contributed by Eldon Ziegler; :issue:`3972`.) +* The :mod:`ihooks` module now supports relative imports. Note that + :mod:`ihooks` is an older module for customizing imports, + superseded by the :mod:`imputil` module added in Python 2.0. + (Relative import support added by Neil Schemenauer.) + + .. revision 75423 + * The :mod:`imaplib` module now supports IPv6 addresses. (Contributed by Derek Morr; :issue:`1655`.) @@ -997,9 +1284,9 @@ changes, or look through the Subversion logs for all the details. >>> def f(a, b=1, *pos, **named): ... pass >>> getcallargs(f, 1, 2, 3) - {'a': 1, 'named': {}, 'b': 2, 'pos': (3,)} + {'a': 1, 'b': 2, 'pos': (3,), 'named': {}} >>> getcallargs(f, a=2, x=4) - {'a': 2, 'named': {'x': 4}, 'b': 1, 'pos': ()} + {'a': 2, 'b': 1, 'pos': (), 'named': {'x': 4}} >>> getcallargs(f) Traceback (most recent call last): ... @@ -1050,8 +1337,8 @@ changes, or look through the Subversion logs for all the details. floats or :class:`~decimal.Decimal` instances. (Implemented by Raymond Hettinger; :issue:`5032`.) - :func:`itertools.combinations` and :func:`itertools.product` were - previously raising :exc:`ValueError` for values of *r* larger than + :func:`itertools.combinations` and :func:`itertools.product` + previously raised :exc:`ValueError` for values of *r* larger than the input iterable. This was deemed a specification error, so they now return an empty iterator. (Fixed by Raymond Hettinger; :issue:`4816`.) @@ -1065,6 +1352,12 @@ changes, or look through the Subversion logs for all the details. with any object literal that decodes to a list of pairs. (Contributed by Raymond Hettinger; :issue:`5381`.) +* The :mod:`mailbox` module's :class:`Maildir` class now records the + timestamp on the directories it reads, and only re-reads them if the + modification time has subsequently changed. This improves + performance by avoiding unneeded directory scans. (Fixed by + A.M. Kuchling and Antoine Pitrou; :issue:`1607951`, :issue:`6896`.) + * New functions: the :mod:`math` module gained :func:`~math.erf` and :func:`~math.erfc` for the error function and the complementary error function, :func:`~math.expm1` which computes ``e**x - 1`` with more precision than @@ -1095,7 +1388,8 @@ changes, or look through the Subversion logs for all the details. real, effective, and saved GIDs and UIDs; :func:`~os.setresgid` and :func:`~os.setresuid`, which set real, effective, and saved GIDs and UIDs to new values; - :func:`~os.initgroups`. (GID/UID functions + :func:`~os.initgroups`, which initialize the group access list + for the current process. (GID/UID functions contributed by Travis H.; :issue:`6508`. Support for initgroups added by Jean-Paul Calderone; :issue:`7333`.) @@ -1117,6 +1411,20 @@ changes, or look through the Subversion logs for all the details. now accept an optional *flags* argument, for consistency with the other functions in the module. (Added by Gregory P. Smith.) +* New function: :func:`~runpy.run_path` in the :mod:`runpy` module + will execute the code at a provided *path* argument. *path* can be + the path of a Python source file (:file:`example.py`), a compiled + bytecode file (:file:`example.pyc`), a directory + (:file:`./package/`), or a zip archive (:file:`example.zip`). If a + directory or zip path is provided, it will be added to the front of + ``sys.path`` and the module :mod:`__main__` will be imported. It's + expected that the directory or zip contains a :file:`__main__.py`; + if it doesn't, some other :file:`__main__.py` might be imported from + a location later in ``sys.path``. This makes some of the machinery + of :mod:`runpy` available to scripts that want to mimic the way + Python's :option:`-m` processes an explicit path name. + (Added by Nick Coghlan; :issue:`6816`.) + * New function: in the :mod:`shutil` module, :func:`~shutil.make_archive` takes a filename, archive type (zip or tar-format), and a directory path, and creates an archive containing the directory's contents. @@ -1128,12 +1436,17 @@ changes, or look through the Subversion logs for all the details. named pipes like a regular file by opening them for reading, and this would block indefinitely. (Fixed by Antoine Pitrou; :issue:`3002`.) +* The :mod:`signal` module no longer re-installs the signal handler + unless this is truly necessary, which fixes a bug that could make it + impossible to catch the EINTR signal robustly. (Fixed by + Charles-Francois Natali; :issue:`8354`.) + * New functions: in the :mod:`site` module, three new functions return various site- and user-specific paths. :func:`~site.getsitepackages` returns a list containing all - global site-packages directories, and + global site-packages directories, :func:`~site.getusersitepackages` returns the path of the user's - site-packages directory. + site-packages directory, and :func:`~site.getuserbase` returns the value of the :envvar:`USER_BASE` environment variable, giving the path to a directory that can be used to store data. @@ -1144,20 +1457,7 @@ changes, or look through the Subversion logs for all the details. catch and swallow the :exc:`KeyboardInterrupt` exception. (Fixed by Victor Stinner; :issue:`3137`.) -* The :mod:`socket` module's :class:`~ssl.SSL` objects now support the - buffer API, which fixed a test suite failure (fix by Antoine Pitrou; - :issue:`7133`). :class:`SSL` objects also now automatically set - OpenSSL's :cmacro:`SSL_MODE_AUTO_RETRY`, which will prevent an error - code being returned from :meth:`recv` operations that trigger an SSL - renegotiation (fix by Antoine Pitrou; :issue:`8222`). - - The version of OpenSSL being used is now available as the module - attributes :attr:`OPENSSL_VERSION` (a string), - :attr:`OPENSSL_VERSION_INFO` (a 5-tuple), and - :attr:`OPENSSL_VERSION_NUMBER` (an integer). (Added by Antoine - Pitrou; :issue:`8321`.) - - The :func:`~socket.create_connection` function +* The :func:`~socket.create_connection` function gained a *source_address* parameter, a ``(host, port)`` 2-tuple giving the source address that will be used for the connection. (Contributed by Eldon Ziegler; :issue:`3972`.) @@ -1168,11 +1468,16 @@ changes, or look through the Subversion logs for all the details. Antoine Pitrou; :issue:`8104`.) * The :mod:`SocketServer` module's :class:`~SocketServer.TCPServer` class now - has a :attr:`~SocketServer.TCPServer.disable_nagle_algorithm` class attribute. - The default value is False; if overridden to be True, + supports socket timeouts and disabling the Nagle algorithm. + The :attr:`~SocketServer.TCPServer.disable_nagle_algorithm` class attribute + defaults to False; if overridden to be True, new request connections will have the TCP_NODELAY option set to prevent buffering many small sends into a single TCP packet. - (Contributed by Kristjan Valur Jonsson; :issue:`6192`.) + The :attr:`~SocketServer.TCPServer.timeout` class attribute can hold + a timeout in seconds that will be applied to the request socket; if + no request is received within that time, :meth:`handle_timeout` + will be called and :meth:`handle_request` will return. + (Contributed by Kristján Valur Jónsson; :issue:`6192` and :issue:`6267`.) * Updated module: the :mod:`sqlite3` module has been updated to version 2.6.0 of the `pysqlite package <http://code.google.com/p/pysqlite/>`__. Version 2.6.0 includes a number of bugfixes, and adds @@ -1181,6 +1486,32 @@ changes, or look through the Subversion logs for all the details. and then call :meth:`~sqlite3.Connection.load_extension` to load a particular shared library. (Updated by Gerhard Häring.) +* The :mod:`ssl` module's :class:`ssl.SSLSocket` objects now support the + buffer API, which fixed a test suite failure (fix by Antoine Pitrou; + :issue:`7133`) and automatically set + OpenSSL's :cmacro:`SSL_MODE_AUTO_RETRY`, which will prevent an error + code being returned from :meth:`recv` operations that trigger an SSL + renegotiation (fix by Antoine Pitrou; :issue:`8222`). + + The :func:`ssl.wrap_socket` constructor function now takes a + *ciphers* argument that's a string listing the encryption algorithms + to be allowed; the format of the string is described + `in the OpenSSL documentation + <http://www.openssl.org/docs/apps/ciphers.html#CIPHER_LIST_FORMAT>`__. + (Added by Antoine Pitrou; :issue:`8322`.) + + Another change makes the extension load all of OpenSSL's ciphers and + digest algorithms so that they're all available. Some SSL + certificates couldn't be verified, reporting an "unknown algorithm" + error. (Reported by Beda Kosata, and fixed by Antoine Pitrou; + :issue:`8484`.) + + The version of OpenSSL being used is now available as the module + attributes :data:`ssl.OPENSSL_VERSION` (a string), + :data:`ssl.OPENSSL_VERSION_INFO` (a 5-tuple), and + :data:`ssl.OPENSSL_VERSION_NUMBER` (an integer). (Added by Antoine + Pitrou; :issue:`8321`.) + * The :mod:`struct` module will no longer silently ignore overflow errors when a value is too large for a particular integer format code (one of ``bBhHiIlLqQ``); it now always raises a @@ -1216,6 +1547,10 @@ changes, or look through the Subversion logs for all the details. false for ones that are implicitly global. (Contributed by Jeremy Hylton.) +* The :mod:`syslog` module will now use the value of ``sys.argv[0]`` as the + identifier instead of the previous default value of ``'python'``. + (Changed by Sean Reifschneider; :issue:`8451`.) + * The ``sys.version_info`` value is now a named tuple, with attributes named :attr:`major`, :attr:`minor`, :attr:`micro`, :attr:`releaselevel`, and :attr:`serial`. (Contributed by Ross @@ -1237,7 +1572,7 @@ changes, or look through the Subversion logs for all the details. :mod:`tarfile` now supports filtering the :class:`~tarfile.TarInfo` objects being added to a tar file. When you call :meth:`~tarfile.TarFile.add`, - instance, you may supply an optional *filter* argument + you may supply an optional *filter* argument that's a callable. The *filter* callable will be passed the :class:`~tarfile.TarInfo` for every file being added, and can modify and return it. If the callable returns ``None``, the file will be excluded from the @@ -1262,8 +1597,39 @@ changes, or look through the Subversion logs for all the details. and has been updated to version 5.2.0 (updated by Florent Xicluna; :issue:`8024`). -* The :class:`~UserDict.UserDict` class is now a new-style class. (Changed by - Benjamin Peterson.) +* The :mod:`urlparse` module's :func:`~urlparse.urlsplit` now handles + unknown URL schemes in a fashion compliant with :rfc:`3986`: if the + URL is of the form ``"<something>://..."``, the text before the + ``://`` is treated as the scheme, even if it's a made-up scheme that + the module doesn't know about. This change may break code that + worked around the old behaviour. For example, Python 2.6.4 or 2.5 + will return the following: + + >>> import urlparse + >>> urlparse.urlsplit('invented://host/filename?query') + ('invented', '', '//host/filename?query', '', '') + + Python 2.7 (and Python 2.6.5) will return: + + >>> import urlparse + >>> urlparse.urlsplit('invented://host/filename?query') + ('invented', 'host', '/filename?query', '', '') + + (Python 2.7 actually produces slightly different output, since it + returns a named tuple instead of a standard tuple.) + + The :mod:`urlparse` module also supports IPv6 literal addresses as defined by + :rfc:`2732` (contributed by Senthil Kumaran; :issue:`2987`). :: + + >>> urlparse.urlparse('http://[1080::8:800:200C:417A]/foo') + ParseResult(scheme='http', netloc='[1080::8:800:200C:417A]', + path='/foo', params='', query='', fragment='') + +* New class: the :class:`~weakref.WeakSet` class in the :mod:`weakref` + module is a set that only holds weak references to its elements; elements + will be removed once there are no references pointing to them. + (Originally implemented in Python 3.x by Raymond Hettinger, and backported + to 2.7 by Michael Foord.) * The ElementTree library, :mod:`xml.etree`, no longer escapes ampersands and angle brackets when outputting an XML processing @@ -1271,13 +1637,22 @@ changes, or look through the Subversion logs for all the details. or comment (which looks like ``<!-- comment -->``). (Patch by Neil Muller; :issue:`2746`.) +* The XML-RPC client and server, provided by the :mod:`xmlrpclib` and + :mod:`SimpleXMLRPCServer` modules, have improved performance by + supporting HTTP/1.1 keep-alive and by optionally using gzip encoding + to compress the XML being exchanged. The gzip compression is + controlled by the :attr:`encode_threshold` attribute of + :class:`SimpleXMLRPCRequestHandler`, which contains a size in bytes; + responses larger than this will be compressed. + (Contributed by Kristján Valur Jónsson; :issue:`6267`.) + * The :mod:`zipfile` module's :class:`~zipfile.ZipFile` now supports the context - management protocol, so you can write ``with zipfile.ZipFile(...) as f: ...``. + management protocol, so you can write ``with zipfile.ZipFile(...) as f:``. (Contributed by Brian Curtin; :issue:`5511`.) - :mod:`zipfile` now supports archiving empty directories and + :mod:`zipfile` now also supports archiving empty directories and extracts them correctly. (Fixed by Kuba Wieczorek; :issue:`4710`.) - Reading files out of an archive is now faster, and interleaving + Reading files out of an archive is faster, and interleaving :meth:`~zipfile.ZipFile.read` and :meth:`~zipfile.ZipFile.readline` now works correctly. (Contributed by Nir Aides; :issue:`7610`.) @@ -1291,36 +1666,157 @@ changes, or look through the Subversion logs for all the details. :issue:`6003`.) +.. ====================================================================== +.. whole new modules get described in subsections here + + +.. _importlib-section: + +New module: importlib +------------------------------ + +Python 3.1 includes the :mod:`importlib` package, a re-implementation +of the logic underlying Python's :keyword:`import` statement. +:mod:`importlib` is useful for implementors of Python interpreters and +to users who wish to write new importers that can participate in the +import process. Python 2.7 doesn't contain the complete +:mod:`importlib` package, but instead has a tiny subset that contains +a single function, :func:`~importlib.import_module`. + +``import_module(name, package=None)`` imports a module. *name* is +a string containing the module or package's name. It's possible to do +relative imports by providing a string that begins with a ``.`` +character, such as ``..utils.errors``. For relative imports, the +*package* argument must be provided and is the name of the package that +will be used as the anchor for +the relative import. :func:`~importlib.import_module` both inserts the imported +module into ``sys.modules`` and returns the module object. + +Here are some examples:: + + >>> from importlib import import_module + >>> anydbm = import_module('anydbm') # Standard absolute import + >>> anydbm + <module 'anydbm' from '/p/python/Lib/anydbm.py'> + >>> # Relative import + >>> file_util = import_module('..file_util', 'distutils.command') + >>> file_util + <module 'distutils.file_util' from '/python/Lib/distutils/file_util.pyc'> + +:mod:`importlib` was implemented by Brett Cannon and introduced in +Python 3.1. + + New module: sysconfig --------------------------------- -XXX A new :mod:`sysconfig` module has been extracted from -:mod:`distutils` and put in the standard library. +The :mod:`sysconfig` module has been pulled out of the Distutils +package, becoming a new top-level module in its own right. +:mod:`sysconfig` provides functions for getting information about +Python's build process: compiler switches, installation paths, the +platform name, and whether Python is running from its source +directory. -The :mod:`sysconfig` module provides access to Python's configuration -information like the list of installation paths and the configuration -variables relevant for the current platform. (contributed by Tarek) +Some of the functions in the module are: -Updated module: ElementTree 1.3 ---------------------------------- +* :func:`~sysconfig.get_config_var` returns variables from Python's + Makefile and the :file:`pyconfig.h` file. +* :func:`~sysconfig.get_config_vars` returns a dictionary containing + all of the configuration variables. +* :func:`~sysconfig.getpath` returns the configured path for + a particular type of module: the standard library, + site-specific modules, platform-specific modules, etc. +* :func:`~sysconfig.is_python_build` returns true if you're running a + binary from a Python source tree, and false otherwise. -XXX write this. +Consult the :mod:`sysconfig` documentation for more details and for +a complete list of functions. -.. ====================================================================== -.. whole new modules get described in subsections here +The Distutils package and :mod:`sysconfig` are now maintained by Tarek +Ziadé, who has also started a Distutils2 package (source repository at +http://hg.python.org/distutils2/) for developing a next-generation +version of Distutils. + + +ttk: Themed Widgets for Tk +-------------------------- + +Tcl/Tk 8.5 includes a set of themed widgets that re-implement basic Tk +widgets but have a more customizable appearance and can therefore more +closely resemble the native platform's widgets. This widget +set was originally called Tile, but was renamed to Ttk (for "themed Tk") +on being added to Tcl/Tck release 8.5. +To learn more, read the :mod:`ttk` module documentation. You may also +wish to read the Tcl/Tk manual page describing the +Ttk theme engine, available at +http://www.tcl.tk/man/tcl8.5/TkCmd/ttk_intro.htm. Some +screenshots of the Python/Ttk code in use are at +http://code.google.com/p/python-ttk/wiki/Screenshots. -Unit Testing Enhancements +The :mod:`ttk` module was written by Guilherme Polo and added in +:issue:`2983`. An alternate version called ``Tile.py``, written by +Martin Franklin and maintained by Kevin Walzer, was proposed for +inclusion in :issue:`2618`, but the authors argued that Guilherme +Polo's work was more comprehensive. + + +.. _unittest-section: + +Updated module: unittest --------------------------------- -The :mod:`unittest` module was enhanced in several ways. -The progress messages now shows 'x' for expected failures +The :mod:`unittest` module was greatly enhanced; many +new features were added. Most of these features were implemented +by Michael Foord, unless otherwise noted. The enhanced version of +the module is downloadable separately for use with Python versions 2.4 to 2.6, +packaged as the :mod:`unittest2` package, from +http://pypi.python.org/pypi/unittest2. + +When used from the command line, the module can automatically discover +tests. It's not as fancy as `py.test <http://pytest.org>`__ or +`nose <http://code.google.com/p/python-nose/>`__, but provides a simple way +to run tests kept within a set of package directories. For example, +the following command will search the :file:`test/` subdirectory for +any importable test files named ``test*.py``:: + + python -m unittest discover -s test + +Consult the :mod:`unittest` module documentation for more details. +(Developed in :issue:`6001`.) + +The :func:`main` function supports some other new options: + +* :option:`-b` or :option:`--buffer` will buffer the standard output + and standard error streams during each test. If the test passes, + any resulting output will be discarded; on failure, the buffered + output will be displayed. + +* :option:`-c` or :option:`--catch` will cause the control-C interrupt + to be handled more gracefully. Instead of interrupting the test + process immediately, the currently running test will be completed + and then the partial results up to the interruption will be reported. + If you're impatient, a second press of control-C will cause an immediate + interruption. + + This control-C handler tries to avoid causing problems when the code + being tested or the tests being run have defined a signal handler of + their own, by noticing that a signal handler was already set and + calling it. If this doesn't work for you, there's a + :func:`removeHandler` decorator that can be used to mark tests that + should have the control-C handling disabled. + +* :option:`-f` or :option:`--failfast` makes + test execution stop immediately when a test fails instead of + continuing to execute further tests. (Suggested by Cliff Dyer and + implemented by Michael Foord; :issue:`8074`.) + +The progress messages now show 'x' for expected failures and 'u' for unexpected successes when run in verbose mode. (Contributed by Benjamin Peterson.) -Test cases can raise the :exc:`~unittest.SkipTest` exception to skip a test. -(:issue:`1034053`.) -.. XXX describe test discovery (Contributed by Michael Foord; :issue:`6001`.) +Test cases can raise the :exc:`~unittest.SkipTest` exception to skip a +test (:issue:`1034053`). The error messages for :meth:`~unittest.TestCase.assertEqual`, :meth:`~unittest.TestCase.assertTrue`, and :meth:`~unittest.TestCase.assertFalse` @@ -1330,7 +1826,7 @@ True, both the standard error message and any additional message you provide will be printed for failures. (Added by Michael Foord; :issue:`5663`.) The :meth:`~unittest.TestCase.assertRaises` method now -return a context handler when called without providing a callable +returns a context handler when called without providing a callable object to run. For example, you can write this:: with self.assertRaises(KeyError): @@ -1350,7 +1846,7 @@ different module or class. The methods :meth:`~unittest.TestCase.addCleanup` and :meth:`~unittest.TestCase.doCleanups` were added. -:meth:`~unittest.TestCase.addCleanup` allows you to add cleanup functions that +:meth:`~unittest.TestCase.addCleanup` lets you add cleanup functions that will be called unconditionally (after :meth:`~unittest.TestCase.setUp` if :meth:`~unittest.TestCase.setUp` fails, otherwise after :meth:`~unittest.TestCase.tearDown`). This allows for much simpler resource allocation and deallocation during tests @@ -1382,10 +1878,10 @@ GvR worked on merging them into Python's version of :mod:`unittest`. differences in the two strings. This comparison is now used by default when Unicode strings are compared with :meth:`~unittest.TestCase.assertEqual`. -* :meth:`~unittest.TestCase.assertRegexpMatches` checks whether its first argument is a - string matching a regular expression provided as its second argument. - - .. XXX add assertNotRegexpMatches see issue 8038 +* :meth:`~unittest.TestCase.assertRegexpMatches` and + :meth:`~unittest.TestCase.assertNotRegexpMatches` checks whether the + first argument is a string matching or not matching the regular + expression provided as the second argument (:issue:`8038`). * :meth:`~unittest.TestCase.assertRaisesRegexp` checks whether a particular exception is raised, and then also checks that the string representation of @@ -1414,9 +1910,10 @@ GvR worked on merging them into Python's version of :mod:`unittest`. all of the key/value pairs in *first* are found in *second*. * :meth:`~unittest.TestCase.assertAlmostEqual` and :meth:`~unittest.TestCase.assertNotAlmostEqual` test - whether *first* and *second* are approximately equal by computing - their difference, rounding the result to an optionally-specified number - of *places* (the default is 7), and comparing to zero. + whether *first* and *second* are approximately equal. This method + can either round their difference to an optionally-specified number + of *places* (the default is 7) and compare it to zero, or require + the difference to be smaller than a supplied *delta* value. * :meth:`~unittest.TestLoader.loadTestsFromName` properly honors the :attr:`~unittest.TestLoader.suiteClass` attribute of @@ -1428,20 +1925,13 @@ GvR worked on merging them into Python's version of :mod:`unittest`. objects being compared are of the specified type. This function should compare the two objects and raise an exception if they don't match; it's a good idea for the function to provide additional - information about why the two objects are matching, much as the new + information about why the two objects aren't matching, much as the new sequence comparison methods do. :func:`unittest.main` now takes an optional ``exit`` argument. If -False, :func:`~unittest.main` doesn't call :func:`sys.exit`, allowing it to be -used from the interactive interpreter. (Contributed by J. Pablo -Fernández; :issue:`3379`.) - -A new command-line switch, :option:`-f` or :option:`--failfast`, makes -test execution stop immediately when a test fails instead of -continuing to execute further tests. (Suggested by Cliff Dyer and -implemented by Michael Foord; :issue:`8074`.) - -.. XXX document the other new switches +False, :func:`~unittest.main` doesn't call :func:`sys.exit`, allowing +:func:`main` to be used from the interactive interpreter. +(Contributed by J. Pablo Fernández; :issue:`3379`.) :class:`~unittest.TestResult` has new :meth:`~unittest.TestResult.startTestRun` and :meth:`~unittest.TestResult.stopTestRun` methods that are called immediately before @@ -1450,70 +1940,98 @@ and after a test run. (Contributed by Robert Collins; :issue:`5728`.) With all these changes, the :file:`unittest.py` was becoming awkwardly large, so the module was turned into a package and the code split into several files (by Benjamin Peterson). This doesn't affect how the -module is imported. - - -.. _importlib-section: - -importlib: Importing Modules ------------------------------- - -Python 3.1 includes the :mod:`importlib` package, a re-implementation -of the logic underlying Python's :keyword:`import` statement. -:mod:`importlib` is useful for implementors of Python interpreters and -to users who wish to write new importers that can participate in the -import process. Python 2.7 doesn't contain the complete -:mod:`importlib` package, but instead has a tiny subset that contains -a single function, :func:`~importlib.import_module`. - -``import_module(name, package=None)`` imports a module. *name* is -a string containing the module or package's name. It's possible to do -relative imports by providing a string that begins with a ``.`` -character, such as ``..utils.errors``. For relative imports, the -*package* argument must be provided and is the name of the package that -will be used as the anchor for -the relative import. :func:`~importlib.import_module` both inserts the imported -module into ``sys.modules`` and returns the module object. - -Here are some examples:: - - >>> from importlib import import_module - >>> anydbm = import_module('anydbm') # Standard absolute import - >>> anydbm - <module 'anydbm' from '/p/python/Lib/anydbm.py'> - >>> # Relative import - >>> sysconfig = import_module('..sysconfig', 'distutils.command') - >>> sysconfig - <module 'distutils.sysconfig' from '/p/python/Lib/distutils/sysconfig.pyc'> - -:mod:`importlib` was implemented by Brett Cannon and introduced in -Python 3.1. - - -ttk: Themed Widgets for Tk --------------------------- - -Tcl/Tk 8.5 includes a set of themed widgets that re-implement basic Tk -widgets but have a more customizable appearance and can therefore more -closely resemble the native platform's widgets. This widget -set was originally called Tile, but was renamed to Ttk (for "themed Tk") -on being added to Tcl/Tck release 8.5. +module is imported or used. -XXX write a brief discussion and an example here. +.. seealso:: -The :mod:`ttk` module was written by Guilherme Polo and added in -:issue:`2983`. An alternate version called ``Tile.py``, written by -Martin Franklin and maintained by Kevin Walzer, was proposed for -inclusion in :issue:`2618`, but the authors argued that Guilherme -Polo's work was more comprehensive. + http://www.voidspace.org.uk/python/articles/unittest2.shtml + Describes the new features, how to use them, and the + rationale for various design decisions. (By Michael Foord.) +.. _elementtree-section: -Deprecations and Removals -========================= +Updated module: ElementTree 1.3 +--------------------------------- -* :func:`contextlib.nested`, which allows handling more than one context manager - with one :keyword:`with` statement, has been deprecated; :keyword:`with` - supports multiple context managers syntactically now. +The version of the ElementTree library included with Python was updated to +version 1.3. Some of the new features are: + +* The various parsing functions now take a *parser* keyword argument + giving an :class:`XMLParser` instance that will + be used. This makes it possible to override the file's internal encoding:: + + p = ET.XMLParser(encoding='utf-8') + t = ET.XML("""<root/>""", parser=p) + + Errors in parsing XML now raise a :exc:`ParseError` exception, whose + instances have a :attr:`position` attribute + containing a (*line*, *column*) tuple giving the location of the problem. + +* ElementTree's code for converting trees to a string has been + significantly reworked, making it roughly twice as fast in many + cases. The :class:`ElementTree` :meth:`write` and :class:`Element` + :meth:`write` methods now have a *method* parameter that can be + "xml" (the default), "html", or "text". HTML mode will output empty + elements as ``<empty></empty>`` instead of ``<empty/>``, and text + mode will skip over elements and only output the text chunks. If + you set the :attr:`tag` attribute of an element to ``None`` but + leave its children in place, the element will be omitted when the + tree is written out, so you don't need to do more extensive rearrangement + to remove a single element. + + Namespace handling has also been improved. All ``xmlns:<whatever>`` + declarations are now output on the root element, not scattered throughout + the resulting XML. You can set the default namespace for a tree + by setting the :attr:`default_namespace` attribute and can + register new prefixes with :meth:`register_namespace`. In XML mode, + you can use the true/false *xml_declaration* parameter to suppress the + XML declaration. + +* New :class:`Element` method: :meth:`extend` appends the items from a + sequence to the element's children. Elements themselves behave like + sequences, so it's easy to move children from one element to + another:: + + from xml.etree import ElementTree as ET + + t = ET.XML("""<list> + <item>1</item> <item>2</item> <item>3</item> + </list>""") + new = ET.XML('<root/>') + new.extend(t) + + # Outputs <root><item>1</item>...</root> + print ET.tostring(new) + +* New :class:`Element` method: :meth:`iter` yields the children of the + element as a generator. It's also possible to write ``for child in + elem:`` to loop over an element's children. The existing method + :meth:`getiterator` is now deprecated, as is :meth:`getchildren` + which constructs and returns a list of children. + +* New :class:`Element` method: :meth:`itertext` yields all chunks of + text that are descendants of the element. For example:: + + t = ET.XML("""<list> + <item>1</item> <item>2</item> <item>3</item> + </list>""") + + # Outputs ['\n ', '1', ' ', '2', ' ', '3', '\n'] + print list(t.itertext()) + +* Deprecated: using an element as a Boolean (i.e., ``if elem:``) would + return true if the element had any children, or false if there were + no children. This behaviour is confusing -- ``None`` is false, but + so is a childless element? -- so it will now trigger a + :exc:`FutureWarning`. In your code, you should be explicit: write + ``len(elem) != 0`` if you're interested in the number of children, + or ``elem is not None``. + +Fredrik Lundh develops ElementTree and produced the 1.3 version; +you can read his article describing 1.3 at +http://effbot.org/zone/elementtree-13-intro.htm. +Florent Xicluna updated the version included with +Python, after discussions on python-dev and in :issue:`6472`.) .. ====================================================================== @@ -1528,9 +2046,9 @@ Changes to Python's build process and to the C API include: <http://sourceware.org/gdb/current/onlinedocs/gdb/Python.html>`__. When you begin debugging an executable program P, GDB will look for a file named ``P-gdb.py`` and automatically read it. Dave Malcolm - contributed a :file:`python-gdb.py` that adds a number of useful - commands when debugging Python itself. For example, there are - ``py-up`` and ``py-down`` that go up or down one Python stack frame, + contributed a :file:`python-gdb.py` that adds a number of + commands useful when debugging Python itself. For example, + ``py-up`` and ``py-down`` go up or down one Python stack frame, which usually corresponds to several C stack frames. ``py-print`` prints the value of a Python variable, and ``py-bt`` prints the Python stack trace. (Added as a result of :issue:`8032`.) @@ -1543,11 +2061,11 @@ Changes to Python's build process and to the C API include: * :cfunc:`Py_AddPendingCall` is now thread-safe, letting any worker thread submit notifications to the main Python thread. This is particularly useful for asynchronous IO operations. - (Contributed by Kristjan Valur Jonsson; :issue:`4293`.) + (Contributed by Kristján Valur Jónsson; :issue:`4293`.) * New function: :cfunc:`PyCode_NewEmpty` creates an empty code object; only the filename, function name, and first line number are required. - This is useful to extension modules that are attempting to + This is useful for extension modules that are attempting to construct a more useful traceback stack. Previously such extensions needed to call :cfunc:`PyCode_New`, which had many more arguments. (Added by Jeffrey Yasskin.) @@ -1555,7 +2073,7 @@ Changes to Python's build process and to the C API include: * New function: :cfunc:`PyErr_NewExceptionWithDoc` creates a new exception class, just as the existing :cfunc:`PyErr_NewException` does, but takes an extra ``char *`` argument containing the docstring for the - new exception class. (Added by the 'lekma' user on the Python bug tracker; + new exception class. (Added by 'lekma' on the Python bug tracker; :issue:`7033`.) * New function: :cfunc:`PyFrame_GetLineNumber` takes a frame object @@ -1576,6 +2094,28 @@ Changes to Python's build process and to the C API include: :cfunc:`PyOS_ascii_strtod` and :cfunc:`PyOS_ascii_atof` functions are now deprecated. +* New function: :cfunc:`PySys_SetArgvEx` sets the value of + ``sys.argv`` and can optionally update ``sys.path`` to include the + directory containing the script named by ``sys.argv[0]`` depending + on the value of an *updatepath* parameter. + + This function was added to close a security hole for applications + that embed Python. The old function, :cfunc:`PySys_SetArgv`, would + always update ``sys.path``, and sometimes it would add the current + directory. This meant that, if you ran an application embedding + Python in a directory controlled by someone else, attackers could + put a Trojan-horse module in the directory (say, a file named + :file:`os.py`) that your application would then import and run. + + If you maintain a C/C++ application that embeds Python, check + whether you're calling :cfunc:`PySys_SetArgv` and carefully consider + whether the application should be using :cfunc:`PySys_SetArgvEx` + with *updatepath* set to false. + + Security issue reported as `CVE-2008-5983 + <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-5983>`_; + discussed in :issue:`5753`, and fixed by Antoine Pitrou. + * New macros: the Python header files now define the following macros: :cmacro:`Py_ISALNUM`, :cmacro:`Py_ISALPHA`, @@ -1594,9 +2134,14 @@ Changes to Python's build process and to the C API include: .. XXX these macros don't seem to be described in the c-api docs. +* Removed function: :cmacro:`PyEval_CallObject` is now only available + as a macro. A function version was being kept around to preserve + ABI linking compatibility, but that was in 1997; it can certainly be + deleted by now. (Removed by Antoine Pitrou; :issue:`8276`.) + * New format codes: the :cfunc:`PyFormat_FromString`, - :cfunc:`PyFormat_FromStringV`, and :cfunc:`PyErr_Format` now - accepts ``%lld`` and ``%llu`` format codes for displaying values of + :cfunc:`PyFormat_FromStringV`, and :cfunc:`PyErr_Format` functions now + accept ``%lld`` and ``%llu`` format codes for displaying C's :ctype:`long long` types. (Contributed by Mark Dickinson; :issue:`7228`.) @@ -1610,7 +2155,7 @@ Changes to Python's build process and to the C API include: ever release the lock, since the other threads weren't replicated, and the child process would no longer be able to perform imports. - Python 2.7 now acquires the import lock before performing an + Python 2.7 acquires the import lock before performing an :func:`os.fork`, and will also clean up any locks created using the :mod:`threading` module. C extension modules that have internal locks, or that call :cfunc:`fork()` themselves, will not benefit @@ -1623,6 +2168,12 @@ Changes to Python's build process and to the C API include: being raised when an interpreter shuts down. (Patch by Adam Olsen; :issue:`1722344`.) +* When using the :ctype:`PyMemberDef` structure to define attributes + of a type, Python will no longer let you try to delete or set a + :const:`T_STRING_INPLACE` attribute. + + .. rev 79644 + * Global symbols defined by the :mod:`ctypes` module are now prefixed with ``Py``, or with ``_ctypes``. (Implemented by Thomas Heller; :issue:`3102`.) @@ -1631,15 +2182,15 @@ Changes to Python's build process and to the C API include: building the :mod:`pyexpat` module to use the system Expat library. (Contributed by Arfrever Frehtes Taifersar Arahesis; :issue:`7609`.) -* New configure option: compiling Python with the +* New configure option: the :option:`--with-valgrind` option will now disable the pymalloc allocator, which is difficult for the Valgrind memory-error detector to analyze correctly. Valgrind will therefore be better at detecting memory leaks and overruns. (Contributed by James Henstridge; :issue:`2422`.) -* New configure option: you can now supply no arguments to - :option:`--with-dbmliborder=` in order to build none of the various +* New configure option: you can now supply an empty string to + :option:`--with-dbmliborder=` in order to disable all of the various DBM modules. (Added by Arfrever Frehtes Taifersar Arahesis; :issue:`6491`.) @@ -1660,6 +2211,52 @@ Changes to Python's build process and to the C API include: Arfrever Frehtes Taifersar Arahesis; :issue:`6094`.) +.. _whatsnew27-capsules: + +Capsules +------------------- + +Python 3.1 adds a new C datatype, :ctype:`PyCapsule`, for providing a +C API to an extension module. A capsule is essentially the holder of +a C ``void *`` pointer, and is made available as a module attribute; for +example, the :mod:`socket` module's API is exposed as ``socket.CAPI``, +and :mod:`unicodedata` exposes ``ucnhash_CAPI``. Other extensions +can import the module, access its dictionary to get the capsule +object, and then get the ``void *`` pointer, which will usually point +to an array of pointers to the module's various API functions. + +There is an existing data type already used for this, +:ctype:`PyCObject`, but it doesn't provide type safety. Evil code +written in pure Python could cause a segmentation fault by taking a +:ctype:`PyCObject` from module A and somehow substituting it for the +:ctype:`PyCObject` in module B. Capsules know their own name, +and getting the pointer requires providing the name:: + + void *vtable; + + if (!PyCapsule_IsValid(capsule, "mymodule.CAPI") { + PyErr_SetString(PyExc_ValueError, "argument type invalid"); + return NULL; + } + + vtable = PyCapsule_GetPointer(capsule, "mymodule.CAPI"); + +You are assured that ``vtable`` points to whatever you're expecting. +If a different capsule was passed in, :cfunc:`PyCapsule_IsValid` would +detect the mismatched name and return false. Refer to +:ref:`using-capsules` for more information on using these objects. + +Python 2.7 now uses capsules internally to provide various +extension-module APIs, but the :cfunc:`PyCObject_AsVoidPtr` was +modified to handle capsules, preserving compile-time compatibility +with the :ctype:`CObject` interface. Use of +:cfunc:`PyCObject_AsVoidPtr` will signal a +:exc:`PendingDeprecationWarning`, which is silent by default. + +Implemented in Python 3.1 and backported to 2.7 by Larry Hastings; +discussed in :issue:`5630`. + + .. ====================================================================== Port-Specific Changes: Windows @@ -1672,16 +2269,24 @@ Port-Specific Changes: Windows and :data:`LIBRARIES_ASSEMBLY_NAME_PREFIX`. (Contributed by David Cournapeau; :issue:`4365`.) +* The :mod:`_winreg` module for accessing the registry now implements + the :func:`CreateKeyEx` and :func:`DeleteKeyEx` functions, extended + versions of previously-supported functions that take several extra + arguments. The :func:`DisableReflectionKey`, + :func:`EnableReflectionKey`, and :func:`QueryReflectionKey` were also + tested and documented. + (Implemented by Brian Curtin: :issue:`7347`.) + * The new :cfunc:`_beginthreadex` API is used to start threads, and the native thread-local storage functions are now used. - (Contributed by Kristjan Valur Jonsson; :issue:`3582`.) + (Contributed by Kristján Valur Jónsson; :issue:`3582`.) * The :func:`os.kill` function now works on Windows. The signal value can be the constants :const:`CTRL_C_EVENT`, - :const:`CTRL_BREAK_EVENT`, or any integer. The Control-C and - Control-Break keystroke events can be sent to subprocesses; any - other value will use the :cfunc:`TerminateProcess` API. - (Contributed by Miki Tebeka; :issue:`1220212`.) + :const:`CTRL_BREAK_EVENT`, or any integer. The first two constants + will send Control-C and Control-Break keystroke events to + subprocesses; any other value will use the :cfunc:`TerminateProcess` + API. (Contributed by Miki Tebeka; :issue:`1220212`.) * The :func:`os.listdir` function now correctly fails for an empty path. (Fixed by Hirokazu Yamamoto; :issue:`5913`.) @@ -1700,18 +2305,29 @@ Port-Specific Changes: Mac OS X installation and a user-installed copy of the same version. (Changed by Ronald Oussoren; :issue:`4865`.) +Port-Specific Changes: FreeBSD +----------------------------------- + +* FreeBSD 7.1's :const:`SO_SETFIB` constant, used with + :func:`~socket.getsockopt`/:func:`~socket.setsockopt` to select an + alternate routing table, is now available in the :mod:`socket` + module. (Added by Kyle VanderBeek; :issue:`8235`.) Other Changes and Fixes ======================= * Two benchmark scripts, :file:`iobench` and :file:`ccbench`, were added to the :file:`Tools` directory. :file:`iobench` measures the - speed of built-in file I/O objects (as returned by :func:`open`) + speed of the built-in file I/O objects returned by :func:`open` while performing various operations, and :file:`ccbench` is a concurrency benchmark that tries to measure computing throughput, thread switching latency, and IO processing bandwidth when performing several tasks using a varying number of threads. +* The :file:`Tools/i18n/msgfmt.py` script now understands plural + forms in :file:`.po` files. (Fixed by Martin von Löwis; + :issue:`5464`.) + * When importing a module from a :file:`.pyc` or :file:`.pyo` file with an existing :file:`.py` counterpart, the :attr:`co_filename` attributes of the resulting code objects are overwritten when the @@ -1747,14 +2363,13 @@ Porting to Python 2.7 This section lists previously described changes and other bugfixes that may require changes to your code: -* When using :class:`Decimal` instances with a string's - :meth:`format` method, the default alignment was previously - left-alignment. This has been changed to right-alignment, which might - change the output of your programs. - (Changed by Mark Dickinson; :issue:`6857`.) +* The :func:`range` function processes its arguments more + consistently; it will now call :meth:`__int__` on non-float, + non-integer arguments that are supplied to it. (Fixed by Alexander + Belopolsky; :issue:`1533`.) - Another :meth:`format`-related change: the default precision used - for floating-point and complex numbers was changed from 6 decimal +* The string :meth:`format` method changed the default precision used + for floating-point and complex numbers from 6 decimal places to 12, which matches the precision used by :func:`str`. (Changed by Eric Smith; :issue:`5920`.) @@ -1764,18 +2379,79 @@ that may require changes to your code: affects new-style classes (derived from :class:`object`) and C extension types. (:issue:`6101`.) -* The :meth:`readline` method of :class:`StringIO` objects now does - nothing when a negative length is requested, as other file-like - objects do. (:issue:`7348`). +* Due to a bug in Python 2.6, the *exc_value* parameter to + :meth:`__exit__` methods was often the string representation of the + exception, not an instance. This was fixed in 2.7, so *exc_value* + will be an instance as expected. (Fixed by Florent Xicluna; + :issue:`7853`.) + +* When a restricted set of attributes were set using ``__slots__``, + deleting an unset attribute would not raise :exc:`AttributeError` + as you would expect. Fixed by Benjamin Peterson; :issue:`7604`.) In the standard library: +* Operations with :class:`datetime` instances that resulted in a year + falling outside the supported range didn't always raise + :exc:`OverflowError`. Such errors are now checked more carefully + and will now raise the exception. (Reported by Mark Leander, patch + by Anand B. Pillai and Alexander Belopolsky; :issue:`7150`.) + +* When using :class:`Decimal` instances with a string's + :meth:`format` method, the default alignment was previously + left-alignment. This has been changed to right-alignment, which might + change the output of your programs. + (Changed by Mark Dickinson; :issue:`6857`.) + + Comparisons involving a signaling NaN value (or ``sNAN``) now signal + :const:`InvalidOperation` instead of silently returning a true or + false value depending on the comparison operator. Quiet NaN values + (or ``NaN``) are now hashable. (Fixed by Mark Dickinson; + :issue:`7279`.) + * The ElementTree library, :mod:`xml.etree`, no longer escapes ampersands and angle brackets when outputting an XML processing instruction (which looks like `<?xml-stylesheet href="#style1"?>`) or comment (which looks like `<!-- comment -->`). (Patch by Neil Muller; :issue:`2746`.) +* The :meth:`readline` method of :class:`StringIO` objects now does + nothing when a negative length is requested, as other file-like + objects do. (:issue:`7348`). + +* The :mod:`syslog` module will now use the value of ``sys.argv[0]`` as the + identifier instead of the previous default value of ``'python'``. + (Changed by Sean Reifschneider; :issue:`8451`.) + +* The :mod:`tarfile` module's default error handling has changed, to + no longer suppress fatal errors. The default error level was previously 0, + which meant that errors would only result in a message being written to the + debug log, but because the debug log is not activated by default, + these errors go unnoticed. The default error level is now 1, + which raises an exception if there's an error. + (Changed by Lars Gustäbel; :issue:`7357`.) + +* The :mod:`urlparse` module's :func:`~urlparse.urlsplit` now handles + unknown URL schemes in a fashion compliant with :rfc:`3986`: if the + URL is of the form ``"<something>://..."``, the text before the + ``://`` is treated as the scheme, even if it's a made-up scheme that + the module doesn't know about. This change may break code that + worked around the old behaviour. For example, Python 2.6.4 or 2.5 + will return the following: + + >>> import urlparse + >>> urlparse.urlsplit('invented://host/filename?query') + ('invented', '', '//host/filename?query', '', '') + + Python 2.7 (and Python 2.6.5) will return: + + >>> import urlparse + >>> urlparse.urlsplit('invented://host/filename?query') + ('invented', 'host', '/filename?query', '', '') + + (Python 2.7 actually produces slightly different output, since it + returns a named tuple instead of a standard tuple.) + For C extensions: * C extensions that use integer format codes with the ``PyArg_Parse*`` @@ -1786,6 +2462,14 @@ For C extensions: :cfunc:`PyOS_ascii_strtod` and :cfunc:`PyOS_ascii_atof` functions, which are now deprecated. +For applications that embed Python: + +* The :cfunc:`PySys_SetArgvEx` function was added, letting + applications close a security hole when the existing + :cfunc:`PySys_SetArgv` function was used. Check whether you're + calling :cfunc:`PySys_SetArgv` and carefully consider whether the + application should be using :cfunc:`PySys_SetArgvEx` with + *updatepath* set to false. .. ====================================================================== @@ -1797,5 +2481,6 @@ Acknowledgements The author would like to thank the following people for offering suggestions, corrections and assistance with various drafts of this -article: Ryan Lovett, R. David Murray, Hugh Secker-Walker. +article: Nick Coghlan, Philip Jenvey, Ryan Lovett, R. David Murray, +Hugh Secker-Walker. |