แสดงชื่อและรหัสสำหรับลูกค้าทั้งหมดที่มีอย่างน้อย 2 บัญชี
Show first name and id for all customers with at least 2 accounts.
df_Customers = pd.DataFrame(columns = ['customer_first_name', 'customer_id'])
df_Accounts = pd.DataFrame(columns = ['customer_id'])
df_Customers[df_Customers['customer_id'].isin(df_Accounts['customer_id'].value_counts()[df_Accounts['customer_id'].value_counts() >= 2].index)][['customer_first_name', 'customer_id']]