iteritems：以迭代器对象返回字典键值对
item:以列表形式返回字典键值对
>>> dic = {‘a‘:3,‘c‘:1,‘b‘:2}
>>> print dic.iteritems()
<dictionary-itemiterator object at 0x7fa381599628>
>>> print dic.items()
[(‘a‘, 3), (‘c‘, 1), (‘b‘, 2)]
原文：http://www.cnblogs.com/ymjyqsx/p/6413741.html