update the tutorial to use str.format
diff --git a/Doc/tutorial/datastructures.rst b/Doc/tutorial/datastructures.rst
index 7ecb049..fa71870 100644
--- a/Doc/tutorial/datastructures.rst
+++ b/Doc/tutorial/datastructures.rst
@@ -550,7 +550,7 @@
>>> questions = ['name', 'quest', 'favorite color']
>>> answers = ['lancelot', 'the holy grail', 'blue']
>>> for q, a in zip(questions, answers):
- ... print 'What is your %s? It is %s.' % (q, a)
+ ... 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.