python 序列
序列(sequence)是一组有顺序的对象的集合
N == 序列的长度 == len(sequence)
常用的序列有：字符串、列表、元组
1、序列类型操作符
成员关系操作符 (in, not in)
>>> a = ‘ajdlks‘ >>> print ‘a‘ in a True
2、连接操作符( + )
>>> s1 = ‘boy‘ >>> s2 = ‘girl‘ >>> print s1 + s2 boygirl >>> print s1 + ‘ ‘ + ‘and‘ + ‘ ‘ + s2 boy and girl
3、重复操作符 ( * )
>>> s = ‘boy‘ >>> print s * 5 boyboyboyboyboy
原文：http://www.cnblogs.com/shetunxiang/p/4660205.html