1、大写改为小写

>>> test1 = "abCDEfg"
>>> test1
'abCDEfg'
>>> test1.upper()
'ABCDEFG'

 

2、小写变大写

>>> test1
'abCDEfg'
>>> test1.lower()
'abcdefg'
>>> test1
'abCDEfg'
>>> test1.casefold()
'abcdefg'

 

3、首字母改为大写

>>> test1
'abCDEfg'
>>> test1.capitalize()
'Abcdefg'
>>> test1
'abCDEfg'
>>> test1.title()
'Abcdefg'

 

4、大写变小写、小写变大写

>>> test1
'abCDEfg'
>>> test1.swapcase()
'ABcdeFG'