Remove trailing whitespace.
diff --git a/Doc/tutorial/datastructures.rst b/Doc/tutorial/datastructures.rst
index fa71870..f7e7243 100644
--- a/Doc/tutorial/datastructures.rst
+++ b/Doc/tutorial/datastructures.rst
@@ -214,7 +214,7 @@
    >>> def sum(seq):
    ...     def add(x,y): return x+y
    ...     return reduce(add, seq, 0)
-   ... 
+   ...
    >>> sum(range(1, 11))
    55
    >>> sum([])
@@ -281,7 +281,7 @@
 powerful tool but -- like all powerful tools -- they need to be used carefully,
 if at all.
 
-Consider the following example of a 3x3 matrix held as a list containing three 
+Consider the following example of a 3x3 matrix held as a list containing three
 lists, one list per row::
 
     >>> mat = [
@@ -290,7 +290,7 @@
     ...        [7, 8, 9],
     ...       ]
 
-Now, if you wanted to swap rows and columns, you could use a list 
+Now, if you wanted to swap rows and columns, you could use a list
 comprehension::
 
     >>> print [[row[i] for row in mat] for i in [0, 1, 2]]
@@ -308,7 +308,7 @@
             print row[i],
         print
 
-In real world, you should prefer builtin functions to complex flow statements. 
+In real world, you should prefer builtin functions to complex flow statements.
 The :func:`zip` function would do a great job for this use case::
 
     >>> zip(*mat)
@@ -551,7 +551,7 @@
    >>> answers = ['lancelot', 'the holy grail', 'blue']
    >>> for q, a in zip(questions, answers):
    ...     print 'What is your {0}?  It is {1}.'.format(q, a)
-   ...	
+   ...
    What is your name?  It is lancelot.
    What is your quest?  It is the holy grail.
    What is your favorite color?  It is blue.
@@ -574,7 +574,7 @@
    >>> basket = ['apple', 'orange', 'apple', 'pear', 'orange', 'banana']
    >>> for f in sorted(set(basket)):
    ...     print f
-   ... 	
+   ...
    apple
    banana
    orange