目前是Angela的100天python课程的第15天，我从所有的练习和项目中了解到，函数外部的变量不能在函数内部使用，除非它作为参数传递或者你在函数内部输入“global”。

MENU = {
    "espresso": {
        "ingredients": {
            "water": 50,
            "coffee": 18,
        },
        "cost": 1.5,
    },
    "latte": {
        "ingredients": {
            "water": 200,
            "milk": 150,
            "coffee": 24,
        },
        "cost": 2.5,
    },
    "cappuccino": {
        "ingredients": {
            "water": 250,
            "milk": 100,
            "coffee": 24,
        },
        "cost": 3.0,
    }
}

profit = 0
resources = {
    "water": 300,
    "milk": 200,
    "coffee": 100,
}

def is_resource_sufficient(order_ingredients):
    """Returns True when order can be made, False if ingredients are insufficient."""
    for item in order_ingredients:
        if order_ingredients[item] > resources[item]:
            print(f"​Sorry there is not enough {item}.")
            return False
    return True

def process_coins():
    """Returns the total calculated from coins inserted."""
    print("Please insert coins.")
    total = int(input("how many quarters?: ")) * 0.25
    total += int(input("how many dimes?: ")) * 0.1
    total += int(input("how many nickles?: ")) * 0.05
    total += int(input("how many pennies?: ")) * 0.01
    return total

def is_transaction_successful(money_received, drink_cost):
    """Return True when the payment is accepted, or False if money is insufficient."""
    if money_received >= drink_cost:
        change = round(money_received - drink_cost, 2)
        print(f"Here is ${change} in change.")
        global profit
        profit += drink_cost
        return True
    else:
        print("Sorry that's not enough money. Money refunded.")
        return False

def make_coffee(drink_name, order_ingredients):
    """Deduct the required ingredients from the resources."""
    for item in order_ingredients:
        resources[item] -= order_ingredients[item]
    print(f"Here is your {drink_name} ☕️. Enjoy!")

is_on = True

while is_on:
    choice = input("​What would you like? (espresso/latte/cappuccino): ")
    if choice == "off":
        is_on = False
    elif choice == "report":
        print(f"Water: {resources['water']}ml")
        print(f"Milk: {resources['milk']}ml")
        print(f"Coffee: {resources['coffee']}g")
        print(f"Money: ${profit}")
    else:
        drink = MENU[choice]
        if is_resource_sufficient(drink["ingredients"]):
            payment = process_coins()
            if is_transaction_successful(payment, drink["cost"]):
                make_coffee(choice, drink["ingredients"])

我试着看她的解决方案，发现她的一个函数使用的字典资源没有在函数内部声明，也没有作为参数传递。我的英语不是很好，这就是为什么我很难在互联网上搜索我特别想了解的内容。有人能用这个主题启发我吗？
注意：不建议使用全局
我的代码：
(my如果未将变量设置为全局变量或未将其作为参数传递，则永远不能在函数外部使用变量）

def use_resources(user_order, machine_menu, machine_resources):
    """Deduct the resources needed for the user's order and returns the current resources of the machine after the
    user's order. """
    for menu_ingredients_key in machine_menu[user_order]["ingredients"]:
        # print(menu_ingredients_key)  # REPRESENT KEY water, coffee
        # print(menu[order]["ingredients"][menu_ingredients_key])  # REPRESENT VALUES [50,18]

        for resources_key in machine_resources:
            if resources_key == menu_ingredients_key:
                machine_resources[menu_ingredients_key] -= menu[user_order]["ingredients"][menu_ingredients_key]
    print(f"Here is your {user_order} ☕. Enjoy! Come again :)")

函数如何使用在函数外部声明的资源，而不是作为参数传递的资源？

def make_coffee(drink_name, order_ingredients):
    """Deduct the required ingredients from the resources."""
    for item in order_ingredients:
        resources[item] -= order_ingredients[item]
    print(f"Here is your {drink_name} ☕️. Enjoy!")