python 函数 enumerate
python中enumerate方法，返回一个enumerate类型。参数一般是可以遍历的的东西，比如列表，字符串什么的。python文档中是这么说的：
enumerate(sequence, )
Return an enumerate object. sequence must be a sequence, an iterator, or some other object which sup-
ports iteration. The next() method of the iterator returned by enumerate() returns a tuple containing
a count (from start which defaults to 0) and the corresponding value obtained from iterating over iter-
able. enumerate() is useful for obtaining an indexed series: (0, seq), (1, seq), (2,
seq), ....
For example:
>>> for i, season in enumerate([’Spring’, ’Summer’, ’Fall’, ’Winter’]):
...
print i, season
0 Spring
1 Summer
2 Fall
3 Winter
个人理解是：当你既需要下标，又需要内容时可以用这个函数来解决
以下是我写的例子：
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# 字符串的使用
value_1 = 'fdahkjlzkjfhaqf'
index = 0
for i in value_1: # 不使用enumerate函数
print index, i
index += 1
for index, value in enumerate(value_1): # 使用enumerate函数
print index, value
# 列表的使用
value_2 = ['a', 'b', 'c', 'd']
index = 0
for i in value_2: # 不使用enumerate函数
print index, i
index += 1
for index, value in enumerate(value_2): # 使用enumerate函数
print index, value
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