python的字符串有众多方法，可以在doc文档中查看
示例
转换开头字母为大写
c1="welcome to my python"
>>> c1.capitalize()
'Welcome to my python'
>>> print(c1)
welcome to my python
>>> c2=c1.capitalize()
>>> print(c2)
Welcome to my python
统计出现次数
>>> c1.count('o')
3
find查询
>>> hw='hello world'
>>> hw
'hello world'
>>> hw.find('world')
6
>>> hw[6:]
'world'
split分割
>>> ip1="192.168.1.123"
>>> ip2="192.189.2.33"
>>> ip1.split('.')
['', '', '', '']
分割
ip1.split('.')[-1]
''
连接
>>> ip1=ip1.split('.')
>>> ip1
['', '', '', '']
>>> ".".join(ip1)
'192.168.1.123'
>>> "-------".join(ip1)