将字典中的值一起添加

Question

我正在为我的大学班级创建一个程序，将商品添加到购物车并显示总价格和数量。 这是我的示例代码。 之后我会将这些信息传输到一个类文件中：

shop_cart = {}


item_quantity = int(input('How many items? '))
print()
for i in range(item_quantity):
    print('Item #', i+1, sep=' ')
    item_name = str(input('Item Name: '))
    item_price = float(input('Item Price: '))
    shop_cart[item_name] = item_price
    item_quantity = int(input('Item Quantity: '))
    shop_cart[item_name] = item_price, item_quantity
    print()
print('Shopping Cart: ', shop_cart)
print()    
remove = str(input('Do you want to remove items? (Y/N): '))
if remove == 'Y':
    remove_item = int(input('How many items to remove? '))
    for i in range(remove_item):
        remove_name = str(input('Enter item name to be removed: '))
        del shop_cart[remove_name]
        print(remove_name, 'has been removed from shopping cart.')

print()
print('Shopping Cart: ', shop_cart)
print('Checking out')

我无法将item_price乘以item_quantity ，然后将所有值加在一起以创建“总价值”对象。

Answer 1

由于字典中的值是元组，您可以使用.values()获取所有这些.values() ，然后使用sum将每个元组的所有sum ：

print('Shopping Cart: ', shop_cart)
print('Total: ', sum(price * quantity for price, quantity in shop_cart.values()))

输出

Shopping Cart:  {'Banana': (1.0, 6), 'Apple': (2.0, 5)}                                                                                             
Total:  16.0

Answer 2

from itertools import starmap
import operator as op
total = sum(starmap(op.mul, cart.values())