join和split的常用使用方法

1、split用法示例

>>> line.split()
['a', 'b', 'c', 'd']

>>> line = "a.b.c.d"
>>> line.split()
['a.b.c.d']
>>> line.split(".")
['a', 'b', 'c', 'd']
>>> line.split(".",0)
['a.b.c.d']
>>> line.split(".",1)
['a', 'b.c.d']
>>> line.split(".",2)
['a', 'b', 'c.d']
>>> line.split(".",-1)
['a', 'b', 'c', 'd']
>>> line.split(".",-2)
['a', 'b', 'c', 'd']

 可得出b.split(".",-1)等价于b.split(".")

2、join用法示例

>>> line=["a","b","c","d"]
>>> ' '.join(line)
'a b c d'
>>> '_'.join(line)
'a_b_c_d'
>>> '.'.join(line)
'a.b.c.d'