รายชื่อร้านค้าที่ไม่มีอุปกรณ์ในสต็อก
List the names of shops that have no devices in stock.
shop_df = pd.DataFrame(columns=['Shop_Name', 'Shop_ID']); stock_df = pd.DataFrame(columns=['Shop_Name', 'Shop_ID'])
shop_df[~shop_df['Shop_ID'].isin(stock_df['Shop_ID'])]['Shop_Name']