Question

我制作了一款基于文字的游戏，并且我正在使用字典来实现背包。当我尝试访问我在课堂上制作的商店时，会出现一个错误，即“＃34; buy＆＃34;和＆＃34;出售＆＃34;没有定义，它们是。在你找我之前，我已经向我提出过类似问题的每个查询。这是我的代码：

class openshop():
    def buy():
        t_newcoincount = 0
        shoploop = 0
        print("Would you like to buy a potion of strength for 2 coins(1)\nOr a potion of health for 3 coins(2)?")
        while shoploop == 0:
            choice = input()

        if choice == "1" and backpack["Coins"] >= 2:
            t_newcoincount = backpack["Coins"]-2
            backpack.update({"Coins":t_newcoincount})
            if "Strength Potions" in backpack.keys():
                t_spcount = backpack["Strength Potions"]+1
                backpack["Strength Potions"] = t_spcount
            else:
                backpack["Strength Potions"] = 1
            shoploop = 1

        elif choice == "2" and backpack["Coins"] >= 3:
            t_newcoincount = backpack["Coins"]-3
            backpack.update({"Coins":t_newcoincount})
            if "Health Potions" in backpack.keys():
                t_hpcount = backpack["Health Potions"]+1
                backpack["Health Potions"] = t_hpcount
            else:
                backpack["Health Potions"] = 1
            shoploop = 1

        elif choice == "1" and backpack["Coins"] < 2:
            print("You cannot afford that")
            menu()
        elif choice == "2" and backpack["Coins"] < 3:
            menu()

        else:
            print("PLEASE SELECT A VALID NUMBER")

    menu()

def sell():
    print("What would you like to sell?")
    sellchoice = input()

    if sellchoice == "bronze dagger":
        t_newcoincount = backpack["Coins"]+5
        backpack.update({"Coins":t_newcoincount})
        if "Bronze Dagger" in backpack.keys():
            if backpack["Bronze Dagger"] > 1:
                t_bdcount = backpack["Bronze Dagger"]-1
                backpack["Bronze Dagger"] = t_bdcount
            else:
                del backpack["Bronze Dagger"]
    elif sellchoice == "leather boots":
        t_newcoincount = backpack["Coins"]+5
        backpack.update({"Coins":t_newcoincount})
        if "Leather Boots" in backpack.keys():
            if backpack["Leather Boots"] > 1:
                t_bdcount = backpack["Leather Boots"]-1
                backpack["Leather Boots"] = t_bdcount
            else:
                del backpack["Leather Boots"]

    elif sellchoice == "health potion" or sellchoice == "health potions":
        t_newcoincount = backpack["Coins"]+3
        backpack.update({"Coins":t_newcoincount})
        if "Health Potions" in backpack.keys():
            if backpack["Health Potions"] > 1:
                t_bdcount = backpack["Health Potions"]-1
                backpack["Health Potions"] = t_bdcount
            else:
                del backpack["Health Potions"]

    elif sellchoice == "strength potion" or sellchoice == "strength potions":
        t_newcoincount = backpack["Coins"]+2
        backpack.update({"Coins":t_newcoincount})
        if "Strength Potions" in backpack.keys():
            if backpack["Strength Potions"] > 1:
                t_bdcount = backpack["Strength Potions"]-1
                backpack["Health Potions"] = t_bdcount
            else:
                del backpack["Strength Potions"]


    menu()



def menu():
    for keys,values in (backpack).items():
        print("You have",values,keys)

    print("Would you like to buy(1) or sell(2)?")
    dec = input()
    if dec == "1" or dec == "buy":
        buy()
    elif dec == "2" or dec == "sell":
        sell()


menu()

以下是我用来从不同文件（显然是同一文件夹）访问它的两行：

import Backpack
backpack.openshop()

以下是我收到的错误消息：

Traceback (most recent call last):
  File "C:\Documents and Settings\user\Desktop\Text Based Game\Backpack import test.py", line 1, in <module>
    import Backpack
  File "C:\Documents and Settings\user\Desktop\Text Based Game\Backpack.py", line 11, in <module>
    class openshop():
  File "C:\Documents and Settings\user\Desktop\Text Based Game\Backpack.py", line 110, in openshop
    menu()
  File "C:\Documents and Settings\user\Desktop\Text Based Game\Backpack.py", line 105, in menu
    buy()
NameError: global name 'buy' is not defined

如果我选择＆＃34;出售＆＃34;，只是购买＆＃39;同样的事情就会发生。将被取代将＆＃39; sell＆＃39 ;. 请告诉我发生了什么以及如何解决它，我很困惑!!

Answer 1

我认为你对课程的运作方式感到困惑。这是一个基本模板：

<强> backpack.py

class Openshop:
    def display(self, message):
        print(message)

    def buy(self):
        self.display("You're buying!")

    def sell(self):
        self.display("Got something to sell?")

<强> main.py

from backpack import Openshop

shop = Openshop()
shop.buy()
shop.sell()

以下是您可以使用此示例运行的一些实验：

从方法参数中删除self。怎么了？为什么？
向方法添加更多参数。怎么了？为什么？
重命名方法时会发生什么？
致电Openshop.buy()时会发生什么？为什么？

一旦您对此示例感到满意，请继续并开始将现有逻辑移动到此代码中。

经常测试！（另外，使用REPL - 这是你的朋友！）

Answer 2

由于您的buy()方法是类openshop的方法，因此您需要按如下方式调用它：

openshop.buy()

Answer 3

在你的例子中，买是（试图 - 有其他问题，比如缺少自我论证）类openope的方法，所以你不得不说像openshop.buy（），或者

x = openshop()
x.buy()

但就像我说的那样，还有很多其他问题，代码不能运行这个修复程序。我建议从一些更小的例子开始，以便掌握使用Python类的编程。

Python全局名称没有定义错误，我已经尝试了一切

3 个答案: