如何转换 class 中变量的字符串？

Question

如何使用字符串访问 class 中的变量？

class GameShop:
    ManaPotion = "ManaPotion"
    priceManaPotion = 50
    HealthPotion = "HealthPotion"
    priceHealthPotion = 50
    StaminaPotion = "StaminaPotion"
    priceStaminaPotion = 50

    itemy = {
        ManaPotion: priceManaPotion,
        HealthPotion: priceHealthPotion,
        StaminaPotion: priceStaminaPotion,

    }

shop = GameShop

print(GameShop.priceHealthPotion)

product_name = input("Product Name")
print(f'{GameShop}' + '.price' + f'{product_name}' )

给出结果<class '__main__.GameShop'>.priceproductname

应该是：50

我应该用什么来做这个？

Answer 1

使用itemy词典：

product_name = input("Product Name")
print(f'{GameShop.itemy[product_name]}'

字典确实是您需要的 GameShop class 的唯一部分；我建议甚至不要将 GameShop 设为 class，而只是制作一个字典，这是商品名称和价格的真实来源：

shop_prices = {
    "ManaPotion": 50,
    "HealthPotion": 50,
    "StaminaPotion": 50,
}

然后你可以像这样循环打印价格：

print("Shop prices:")
for item, price in shop_prices.items():
    print(f"\t{item}: {price}")

并使用商品名称作为键在 shop_prices 中查找给定商品的价格：

item = input("What do you want to buy?")
try:
    print(f"That'll be {shop_prices[item]} gold pieces, please.")
except KeyError:
    print(f"Sorry, {item} isn't in this shop.")

Answer 2

或者，如果您仍想使用 class，您可以执行

try:
   price=getattr(shop, f"price{product_name}")
   print(f"The cost of {product_name} is {price}")
except AttributeError:
   print("Sorry, this item is not available")

记住 get_attr 不是一个方法，它将对象作为第一个参数

如何转换 class 中变量的字符串？

How to convert string on variable in class?

python

string