enumerate函数可以同时获取索引，以及值，用next()方法调用。
例1：
>>> s = ‘hello word‘ #########s为可迭代对象
>>> h = enumerate(s)
>>> h
<enumerate object at 0x7f1d66848a50>
>>> h.next()
(0, ‘h‘)
>>> h.next()
(1, ‘e‘)
>>> h.next()
(2, ‘l‘)
>>> h.next()
(3, ‘l‘)
>>> h.next()
(4, ‘o‘)
>>> h.next()
(5, ‘ ‘)
>>> h.next()
(6, ‘w‘)
>>> h.next()
(7, ‘o‘)
>>> h.next()
(8, ‘r‘)
>>> h.next()
(9, ‘d‘)
例2：
>>> for i,j in enumerate(s): ###########用于for循环
... i,j
...
(0, ‘h‘)
(1, ‘e‘)
(2, ‘l‘)
(3, ‘l‘)
(4, ‘o‘)
(5, ‘ ‘)
(6, ‘w‘)
(7, ‘o‘)
(8, ‘r‘)
(9, ‘d‘)
原文：http://weilantiankong.blog.51cto.com/9469693/1754552