Python --如何将每个项目乘以用户输入的数量？

Question

我有这个python3代码，它是一个简单的购物清单，用户可以键入他想要购买的商品，然后输出就是总成本。但是，我不想多次重复每个项目，我希望用户输入的数量像.“2鸡，2番茄”而不是“鸡，鸡，番茄，番茄”，..how，我要这样做吗？

items_dict={"chicken": 50, "fish":30, "tomato":12, "chips":5}
print("Our shop has", tuple(items_dict))
prompt=input("What will you buy?\n").split(', ')
total_price=0

for items in prompt:
    try:
        total_price += items_dict[items]
    except:
        total_price="Some items aren't available to buy."
        break
print ("You have to pay", total_price, "EGP")

输入:2只鸡，22只番茄，100片

预期产出:您必须支付864 EGP。

Answer 1

我应该以以下方式使用re.match来处理这个问题：

import re
items_dict={"chicken": 50, "fish":30, "tomato":12, "chips":5}
print("Our shop has", tuple(items_dict))
prompt=input("What will you buy?\n").split(', ')

total_price=0

for items in prompt:
    match = re.match("(\d+)(\w+)", items) # Here group(1) => (\d+) will match the quantity of item and 
                                          # group(2) => (\w+) will match the name of product.
    try:
        total_price += (int(match.group(1))*items_dict[match.group(2)])
    except:
        total_price="Some items aren't available to buy."
        
print ("You have to pay", total_price, "EGP")

输出：

Our shop has ('chicken', 'fish', 'tomato', 'chips')
What will you buy?
2chicken, 22tomato, 100chips
You have to pay 864 EGP