【Looping Techniques】
1、When looping through dictionaries, the key and corresponding value can be retrieved at the same time using the items() method.
2、enumerate(iterable, start=0)
Return an enumerate object. iterable must be a sequence, an iterator, or some other object which supports iteration. The __next__() method of the iterator returned by enumerate() returns a tuple containing a count (from start which defaults to 0) and the values obtained from iterating over iterable.
Equivalent to:
3、zip
4、sorted
5、reversed
原文：http://www.cnblogs.com/tekkaman/p/5800460.html