根据另一个字典中的价格确定一个字典中的项目成本

Question

在这里，我有一个程序，通过乘以价格和库存来提供单个杂货的总价。但是我应该用什么来找到所有杂货的总价格？

total = 0
prices = {
    "banana" : 4,
    "apple" : 2,
    "orange" : 1.5,
    "pear" : 3
}

stock = {
    "banana" : 9,
    "apple" : 0,
    "orange" : 18,
    "pear" : 22
}

for i in prices:
    print (i.title())
    print ("Price:", prices[i])
    print ("Stock:", stock[i])
    print ("=================")

for key in prices:
    print(key.title() + " Total Price:" , prices[key]*stock[key])

Answer 1

sum(prices[key] * stock[key] for key in prices)

Answer 2

假设您的意思是库存中所有商品的总数，您可以将总数据数据存储在以后易于关键的结构中，从而易于操作：

totals = {k:(stock[k] * prices[k]) for k in prices if k in stock}

In [12]: sum(totals.values())
Out[12]: 129.0