python的dataframe如何进行关系除法？

Question

pandas怎样进行关系除法呢？

import pandas as pd
R = {'A':['a','a','a','b','e','e'],
        'B':['b','b','b','c','d','d'],
        'C':['c','e','d','e','c','e'],
        'D':['d','f','e','f','d','f']}
R = pd.DataFrame(R)
print('R',R)

# dataframe的每一列除以series
S = {'C':['c','e'],
        'D':['d','f'],
    }
S= pd.DataFrame(S)
print('S',S)
#想得到R/S={'A':['a','e'];'B':['b','d']}