str.join(iterable)Return a string which is concatenation the of the strings in the iterable iterable. The separator between elements is the string providing this method.
返回一个以str为间隔，元素是iterable里元素。
>>> a=[‘a‘,‘b‘,‘c‘] >>> a [‘a‘, ‘b‘, ‘c‘] >>> ‘‘.join(a) ‘abc‘ >>> ‘ ‘.join(a) ‘a b c‘
>>> ‘s‘.join(a)
‘asbsc‘
原文：http://www.cnblogs.com/caizhenzhen/p/5094176.html