Python 字符串

1.join()方法"X".join(args)表示用X连接后面的各个数
>>> a="abcd"
>>> ",".join(a)
'a,b,c,d'
>>> ",".join(['a','b','c'])
'a,b,c'
>>> ",".join(('a','b','c'))
'a,b,c'
>>> ",".join({'a':1,'b':2,'c':3})
'a,c,b'

2.os.path.join('a','b','c')>>>abc,把参数连接起来