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| author | Christian Heimes <christian@cheimes.de> | 2008-01-06 17:05:40 (GMT) |
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| committer | Christian Heimes <christian@cheimes.de> | 2008-01-06 17:05:40 (GMT) |
| commit | 7f044315f49836fbe472b53e089e733439ca5ece (patch) | |
| tree | 411215f12c3970bfd47372959fe711887da690bc /Doc/reference | |
| parent | faf2f63faf9e73c816f0a8bf7f5998757280b50a (diff) | |
| download | cpython-7f044315f49836fbe472b53e089e733439ca5ece.zip cpython-7f044315f49836fbe472b53e089e733439ca5ece.tar.gz cpython-7f044315f49836fbe472b53e089e733439ca5ece.tar.bz2 | |
Merged revisions 59774-59783 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
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r59774 | georg.brandl | 2008-01-06 16:41:50 +0100 (Sun, 06 Jan 2008) | 2 lines
#1501: document that 0**0 == 1.
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r59775 | georg.brandl | 2008-01-06 16:48:20 +0100 (Sun, 06 Jan 2008) | 2 lines
#759525: document that dir() doesn't return metaclass attrs when given a class as arg.
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r59776 | georg.brandl | 2008-01-06 16:55:26 +0100 (Sun, 06 Jan 2008) | 2 lines
#1615275: clarify return object types of different tempfile factories.
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r59777 | georg.brandl | 2008-01-06 17:01:26 +0100 (Sun, 06 Jan 2008) | 2 lines
#1727024: document that Popen.returncode is set by Popen.poll/wait.
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r59778 | georg.brandl | 2008-01-06 17:04:56 +0100 (Sun, 06 Jan 2008) | 2 lines
#1686390: add example for csv.Sniffer use.
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r59779 | georg.brandl | 2008-01-06 17:12:39 +0100 (Sun, 06 Jan 2008) | 2 lines
#1559684: document that shutil.copy* doesn't copy all metadata on Posix and Windows too.
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r59780 | georg.brandl | 2008-01-06 17:17:56 +0100 (Sun, 06 Jan 2008) | 2 lines
#1582: document __reversed__, patch by Mark Russell.
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r59781 | georg.brandl | 2008-01-06 17:22:56 +0100 (Sun, 06 Jan 2008) | 2 lines
#1499: Document compile() exceptions.
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r59782 | georg.brandl | 2008-01-06 17:49:50 +0100 (Sun, 06 Jan 2008) | 2 lines
#1325: Add docs and tests for zipimporter.archive and zipimporter.prefix.
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Diffstat (limited to 'Doc/reference')
| -rw-r--r-- | Doc/reference/datamodel.rst | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst index 6acd25a..9c2d7cd 100644 --- a/Doc/reference/datamodel.rst +++ b/Doc/reference/datamodel.rst @@ -1688,6 +1688,20 @@ container; for mappings, :meth:`__iter__` should be the same as Iterator objects also need to implement this method; they are required to return themselves. For more information on iterator objects, see :ref:`typeiter`. + +.. method:: object.__reversed__(self) + + Called (if present) by the :func:`reversed` builtin to implement + reverse iteration. It should return a new iterator object that iterates + over all the objects in the container in reverse order. + + If the :meth:`__reversed__` method is not provided, the + :func:`reversed` builtin will fall back to using the sequence protocol + (:meth:`__len__` and :meth:`__getitem__`). Objects should normally + only provide :meth:`__reversed__` if they do not support the sequence + protocol and an efficient implementation of reverse iteration is possible. + + The membership test operators (:keyword:`in` and :keyword:`not in`) are normally implemented as an iteration through a sequence. However, container objects can supply the following special method with a more efficient implementation, which |