ค้นหาชื่อลูกค้าที่ไม่มีสินเชื่อประเภทจำนอง
Find the name of customers who do not have a loan with a type of Mortgages.
df_loan = pd.DataFrame(columns=['cust_id', 'loan_type']); df_cust = pd.DataFrame(columns=['cust_name', 'cust_id'])
df_cust[~df_cust['cust_id'].isin(df_loan[df_loan['loan_type'] == 'Mortgages']['cust_id'])]['cust_name']