Python如何获取字典第二个键对应值并与订购数量相乘

核心实现逻辑 #

你当前使用的菜单字典为二级嵌套结构，外层字典的key对应选项字母，value为仅包含1组菜名:单价键值对的内层字典。要获取单价（即你所说的第二个对应值）和订购数量做乘法，只需要从选中的内层字典中提取出单价数值即可。

具体修改方法 #

你可以直接在现有代码末尾追加如下计算逻辑：

# 获取选中的菜品字典
selected_dish = menu(option)
# 提取菜名和单价
dish_name = next(iter(selected_dish.keys()))
dish_price = next(iter(selected_dish.values()))
# 计算总金额
total_amount = dish_price * quantity
# 输出订单明细
print(f"你订购的菜品是：{dish_name}，单价：{dish_price}元，数量：{quantity}份，总金额为：{total_amount:.2f}元")

完整可运行代码 #

chowMenu = {'a': {'Fried Chicken': 99.99}, 'b': {'Chao Fan': 60.99}, 'c': {'Siomai': 45.99}, 'd': {'Chop Suey': 30.00}}
print(" ******** Welcome  to Chowpanda!.********")

def menu(userInput):
    return chowMenu.get(userInput,"Oops! it seems that is not on the menu")
print('\n'.join("{}: {}\n-----------------------".format(k, v) for k, v in chowMenu.items()))
option = input('Please choose your order:')

while  option != 'a' and option != 'b' and option != 'c' and option != 'd' :
    print(menu(option))
    option = input('Please choose your order:')
print(menu(option))
quantity = int(input('How many would you like to order?: '))

# 新增金额计算逻辑
selected_dish = menu(option)
dish_name = next(iter(selected_dish.keys()))
dish_price = next(iter(selected_dish.values()))
total_amount = dish_price * quantity
print(f"订单明细：{dish_name} * {quantity} = {total_amount:.2f}元")

其他可选实现方式 #

如果不想用next(iter())的写法，也可以直接把内层字典转列表后取值，逻辑完全等效：

dish_price = list(selected_dish.values())[0]

内容的提问来源于stack exchange，提问作者Brilliant Help