ค้นหาชื่อลูกค้าที่มีวงเงินกู้สูงสุด
Find the name of customer who has the highest amount of loans.
df_loan = pd.DataFrame(columns=['cust_id', 'amount']); df_cust = pd.DataFrame(columns=['cust_name', 'cust_id'])
df_cust.set_index('cust_id').join(df_loan.groupby('cust_id').sum(), on='cust_id').sort_values('amount', ascending=False).iloc[0]['cust_name']