python list 与 string 转换

代码如下：

# -*- coding:utf-8 -*-

str = '3.0.31'

list = str.split('.')

print list

list.append('6789')

print list

var = '.'.join(list)

print var

运行效果如下：

['3', '0', '31']
['3', '0', '31', '6789']
3.0.31.6789