Pandas Groupby Max múltiples columnas en Pandas
annotations.groupby(['bookid','conceptid'], sort=False)['weight'].max()
Lovely Lemur
annotations.groupby(['bookid','conceptid'], sort=False)['weight'].max()
In [11]: df.groupby(['col5', 'col2']).size()
Out[11]:
col5 col2
1 A 1
D 3
2 B 2
3 A 3
C 1
4 B 1
5 B 2
6 B 1
dtype: int64