pandas修改DataFrame列名的方法

>import pandas as pd
>a = pd.DataFrame({'A':[1,2,3], 'B':[4,5,6], 'C':[7,8,9]})
> a 
 A B C
0 1 4 7
1 2 5 8
2 3 6 9

>a.columns = ['a','b','c']
>a
 a b c
0 1 4 7
1 2 5 8
2 3 6 9

>a.rename(columns={'A':'a', 'B':'b', 'C':'c'}, inplace = True)
>a
 a b c
0 1 4 7
1 2 5 8
2 3 6 9

>a.rename(columns={'A':'a', 'C':'c'}, inplace = True)
>a
 a B c
0 1 4 7
1 2 5 8
2 3 6 9