ฝรั่งเศสมีผู้ผลิตรถยนต์กี่ราย?
How many car makers are there in france?
df_COUNTRIES = pd.DataFrame(columns=['CountryId', 'CountryName']); df_CAR_MAKERS = pd.DataFrame(columns=['Country'])
df_CAR_MAKERS[df_CAR_MAKERS['Country'].isin(df_COUNTRIES[df_COUNTRIES['CountryName'] == 'france']['CountryId'])].shape[0]