merge with 3.2

Doc/tutorial/classes.rst

@@ -730,7 +730,6 @@ built-in function; this example shows how it all works::
    >>> next(it)
    'c'
    >>> next(it)
-
    Traceback (most recent call last):
      File "<stdin>", line 1, in ?
        next(it)
@@ -742,7 +741,7 @@ returns an object with a :meth:`__next__` method.  If the class defines
 :meth:`__next__`, then :meth:`__iter__` can just return ``self``::
 
    class Reverse:
-       "Iterator for looping over a sequence backwards"
+       """Iterator for looping over a sequence backwards."""
        def __init__(self, data):
            self.data = data
            self.index = len(data)