คณะกรรมการชุดไหนมีผู้แทนจากทั้งพรรคประชาธิปัตย์และพรรคเสรีนิยม?
Which committees have delegates from both democratic party and liberal party?
df1 = pd.DataFrame(columns=['Committee', 'Party']); df2 = pd.DataFrame(columns=['Party_ID', 'Party'])
df1.loc[df1['Party'].isin(df2.loc[df2['Party'].isin(['Democratic', 'Liberal']), 'Party_ID'])]['Committee'].unique()