python中join字符串方法详解

1string.join（str）分割字符串，用string把str字符串分割开，并且返回产生的新字符串。

In [1]: str = "abcdefg"

In [2]: ",".join(str)
Out[2]: 'a,b,c,d,e,f,g'

2连接列表、元祖、字典（字典里连接的是key）里的字符串元素（这里必须是字符串元素，其他类型会报错），返回一个字符串。

In [3]: dict = {"a":"1","b":"2","c":"3"}

In [4]: "+".join(dict)
Out[4]: 'a+b+c'

In [5]: list = ["a","b","c"]

In [6]: "+".join(list)
Out[6]: 'a+b+c'

In [7]: tup =("a","b","c")

In [8]: "+".join(tup)
Out[8]: 'a+b+c'