ลูกค้าชื่อ Carole และนามสกุล Bernhard จ่ายเงินทั้งหมดเท่าไร?
How much in total does customer with first name as Carole and last name as Bernhard paid?
df_customers = pd.DataFrame(columns=['customer_id', 'first_name', 'last_name'])
df_customer_payments = pd.DataFrame(columns=['amount_payment', 'customer_id'])
df_customer_payments[df_customer_payments['customer_id'].isin(df_customers[(df_customers['first_name'] == 'Carole') & (df_customers['last_name'] == 'Bernhard')]['customer_id'])]['amount_payment'].sum()