Merged revisions 59774-59783 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
........
r59774 | georg.brandl | 2008-01-06 16:41:50 +0100 (Sun, 06 Jan 2008) | 2 lines
#1501: document that 0**0 == 1.
........
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.
........
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.
........
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.
........
r59778 | georg.brandl | 2008-01-06 17:04:56 +0100 (Sun, 06 Jan 2008) | 2 lines
#1686390: add example for csv.Sniffer use.
........
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.
........
r59780 | georg.brandl | 2008-01-06 17:17:56 +0100 (Sun, 06 Jan 2008) | 2 lines
#1582: document __reversed__, patch by Mark Russell.
........
r59781 | georg.brandl | 2008-01-06 17:22:56 +0100 (Sun, 06 Jan 2008) | 2 lines
#1499: Document compile() exceptions.
........
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.
........
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 @@
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