Remove trailing whitespace.
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index 2bd18d0..67646c6 100644
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -76,7 +76,7 @@
 
 .. function:: itertools.chain.from_iterable(iterable)
 
-   Alternate constructor for :func:`chain`.  Gets chained inputs from a 
+   Alternate constructor for :func:`chain`.  Gets chained inputs from a
    single iterable argument that is evaluated lazily.  Equivalent to::
 
       @classmethod
@@ -93,9 +93,9 @@
 
    Return *r* length subsequences of elements from the input *iterable*.
 
-   Combinations are emitted in lexicographic sort order.  So, if the 
+   Combinations are emitted in lexicographic sort order.  So, if the
    input *iterable* is sorted, the combination tuples will be produced
-   in sorted order.  
+   in sorted order.
 
    Elements are treated as unique based on their position, not on their
    value.  So if the input elements are unique, there will be no repeat
@@ -314,7 +314,7 @@
           for i, element in enumerate(iterable):
               if i == nexti:
                   yield element
-                  nexti = it.next()          
+                  nexti = it.next()
 
    If *start* is ``None``, then iteration starts at zero. If *step* is ``None``,
    then the step defaults to one.
@@ -380,12 +380,12 @@
    Return successive *r* length permutations of elements in the *iterable*.
 
    If *r* is not specified or is ``None``, then *r* defaults to the length
-   of the *iterable* and all possible full-length permutations 
+   of the *iterable* and all possible full-length permutations
    are generated.
 
-   Permutations are emitted in lexicographic sort order.  So, if the 
+   Permutations are emitted in lexicographic sort order.  So, if the
    input *iterable* is sorted, the permutation tuples will be produced
-   in sorted order.  
+   in sorted order.
 
    Elements are treated as unique based on their position, not on their
    value.  So if the input elements are unique, there will be no repeat
@@ -416,7 +416,7 @@
                 else:
                     return
 
-   The code for :func:`permutations` can be also expressed as a subsequence of 
+   The code for :func:`permutations` can be also expressed as a subsequence of
    :func:`product`, filtered to exclude entries with repeated elements (those
    from the same position in the input pool)::
 
@@ -564,7 +564,7 @@
    >>> data = [ 1,  4,5,6, 10, 15,16,17,18, 22, 25,26,27,28]
    >>> for k, g in groupby(enumerate(data), lambda (i,x):i-x):
    ...     print map(itemgetter(1), g)
-   ... 
+   ...
    [1]
    [4, 5, 6]
    [10]
@@ -691,7 +691,7 @@
     def unique_everseen(iterable, key=None):
         "List unique elements, preserving order. Remember all elements ever seen."
         # unique_everseen('AAAABBBCCDAABBB') --> A B C D
-        # unique_everseen('ABBCcAD', str.lower) --> A B C D    
+        # unique_everseen('ABBCcAD', str.lower) --> A B C D
         seen = set()
         seen_add = seen.add
         if key is None: