Pandas 文本数据方法 capitalize( ) lower( ) upper( )

import pandas as pd
s = pd.Series(['A', 'B', 'C', 'Aaba', 'Baca', 'CABA', 'dog', 'cat'])
print(s.str.capitalize())
print(s.str.lower())
print(s.str.upper())
0       A
1       B
2       C
3    Aaba
4    Baca
5    Caba
6     Dog
7     Cat
dtype: object

0       a
1       b
2       c
3    aaba
4    baca
5    caba
6     dog
7     cat
dtype: object

0       A
1       B
2       C
3    AABA
4    BACA
5    CABA
6     DOG
7     CAT
dtype: object

0       a
1       b
2       c
3    aABA
4    bACA
5    caba
6     DOG
7     CAT
dtype: object