为什么我的变量不会更新它们的值？

Question

我正在使用 python 制作一个五人营养计算器，并将所有营养信息输入字典。 我有单独的变量，例如碳水化合物、卡路里、蛋白质等，并通过将其中的值与字典中的值相加来更新它们。 字典很长，所以前几个键是

fiveguys_menu = {'burger': {'hamburger':[700, 39, 39, 43, 19.5, 2, 430, 8, 2], 'cheeseburger':[770, 39, 43, 49, 23.5, 2.2, 790, 8, 2],...}

first_food = input("What're you tryna eat?  Please state whether you want a burger or fries, fatty.\n").lower().replace(" ", "")
if 'burger' in first_food:
    while True:
        burger_type = input('Out of hamburger, cheeseburger, baconburger, and bacon cheeseburger, which one do you want?\n').lower().replace(" ", "")
        if 'ham' in burger_type:
            calories = fiveguys_menu['burger']['hamburger'][0]
            carbs = fiveguys_menu['burger']['hamburger'][1]
            protein = fiveguys_menu['burger']['hamburger'][2]
            total_fat = fiveguys_menu['burger']['hamburger'][3]
            sat_fat = fiveguys_menu['burger']['hamburger'][4]
            trans_fat = fiveguys_menu['burger']['hamburger'][5]
            sodium = fiveguys_menu['burger']['hamburger'][6]
            sugar = fiveguys_menu['burger']['hamburger'][7]
            fiber = fiveguys_menu['burger']['hamburger'][8]
            print_message("One hamburger coming up.")
            print(calories, carbs, protein, total_fat, sat_fat, trans_fat, sodium, sugar, fiber)

但是，当尝试使用浇头列表更新宏变量时，变量不会更新。

fiveguys_toppings = {'a1sauce':[15, 3, 0, 0, 0,0, 280, 2, 0], 'barbeque':[60, 15, 0, 0, 0, 0, 400, 10, 0], ...}

while True:
                    burger_toppings = input("The toppings available are A1 Sauce, barbeque, green pepper, grilled mushrooms, hot sauce, jalapenos, ketchup, lettuce, mayo, mustard, onions, pickles, relish, and tomatoes\nWhat toppings do you want?  Please be specific to the spelling listed. \n").lower().replace(" ", "")

                    if burger_toppings == True:
                        calories += fiveguys_toppings[burger_toppings][0]
                        carbs += fiveguys_toppings[burger_toppings][1]
                        protein += fiveguys_toppings[burger_toppings][2]
                        total_fat += fiveguys_toppings[burger_toppings][3]
                        sat_fat += fiveguys_toppings[burger_toppings][4]
                        trans_fat += fiveguys_toppings[burger_toppings][5]
                        sodium += fiveguys_toppings[burger_toppings][6]
                        sugar += fiveguys_toppings[burger_toppings][7]
                        fiber += fiveguys_toppings[burger_toppings][8]
                    print(calories, carbs, protein, total_fat, sat_fat, trans_fat, sodium, sugar, fiber)

为什么这个 while True 循环不更新宏变量？

Answer 1

burger_toppings = input(...) - 所以它将等于输入的内容，而不是 boolean True 。 您可以将 if 语句更改为if burger_toppings: ，如果 burger_toppings 为真（非空字符串、非空列表、非无 object 等），它将评估为 True。

Answer 2

您的代码检查burger_toppings是否为True ，因为它是str ，所以永远不会。 尝试：

fiveguys_toppings = {
    'a1sauce': [15, 3, 0, 0, 0, 0, 280, 2, 0],
    'barbeque': [60, 15, 0, 0, 0, 0, 400, 10, 0], ...}

while True:
    burger_toppings = input(
        "The toppings available are A1 Sauce, barbeque, green pepper, "
        "grilled mushrooms, hot sauce, jalapenos, ketchup, lettuce, mayo, "
        "mustard, onions, pickles, relish, and tomatoes.\n"
        "What toppings do you want?  "
        "Please be specific to the spelling listed.\n"
    ).lower().replace(" ", "")

    if burger_toppings not in fiveguys_toppings:
        print(f"{burger_toppings.capitalize()} is not one of the options!")
        continue

    calories += fiveguys_toppings[burger_toppings][0]
    carbs += fiveguys_toppings[burger_toppings][1]
    protein += fiveguys_toppings[burger_toppings][2]
    total_fat += fiveguys_toppings[burger_toppings][3]
    sat_fat += fiveguys_toppings[burger_toppings][4]
    trans_fat += fiveguys_toppings[burger_toppings][5]
    sodium += fiveguys_toppings[burger_toppings][6]
    sugar += fiveguys_toppings[burger_toppings][7]
    fiber += fiveguys_toppings[burger_toppings][8]
    print(calories, carbs, protein, total_fat, sat_fat, trans_fat, sodium, sugar, fiber)