索引赋值
>>> s = "abcada"
>>> s = list(s)
>>> s
[‘a‘, ‘b‘, ‘c‘, ‘a‘, ‘d‘, ‘a‘]
>>> s[0] = "xx"
>>> s
[‘xx‘, ‘b‘, ‘c‘, ‘a‘, ‘d‘, ‘a‘]
切片赋值
>>> s = "abcada"
>>> s = list(s)
>>> s
[‘a‘, ‘b‘, ‘c‘, ‘a‘, ‘d‘, ‘a‘]
>>> s[0:1] = "xx"
>>> s
[‘x‘, ‘x‘, ‘b‘, ‘c‘, ‘a‘, ‘d‘, ‘a‘]
注意：直接按索引赋值是把值作为一个整体赋值了；
按切片赋值是把值转换为里列表后赋值了；
s[0] 和 s[0:1] 都只是代表0索引位置上的元素原文：http://blog.51cto.com/13496943/2348535