แสดงชื่อโทรศัพท์และเขตตลาดที่เปิดอยู่
Show the names of phones and the districts of markets they are on.
df_phone = pd.DataFrame(columns=['Name', 'Phone_ID']); df_market = pd.DataFrame(columns=['District', 'Market_ID']); df_phone_market = pd.DataFrame(columns=['Market_ID', 'Phone_ID'])
pd.merge(pd.merge(df_phone_market,df_market,on='Market_ID'),df_phone,on='Phone_ID')[['Name', 'District']]