Question

我对编码非常陌生，并且学习了如何使用Python。几天前，我开始学习课程，对他们有些困惑，但是我对课程的练习越多，我就越了解。因此，为了练习，我尝试执行此代码，但始终出现属性错误：

>>> class Hero:
     def __init__(self):
         self.health = 100
     def eat (self, food):
         if food == ham:
             print 'Bob has gained health!'
             self.health+=self.HealthBonus
         elif food == poison:
             print 'Oh no! Bob has taken damage!'
             self.health-=self.HealthDown

>>> class Ham:
     def __init__ (self):
         self.name = 'ham'
         self.HealthBonus = 10

>>> class Poison:
     def __init__ (self):
         self.name = 'poison'
         self.HealthDown = 20

>>> bob=Hero()
>>> ham=Ham()
>>> poison=Poison()
>>> bob.eat(ham)
Bob has gained health!
Traceback (most recent call last):
  File "<pyshell#9>", line 1, in <module>
    bob.eat(ham)
  File "<pyshell#1>", line 7, in eat
    self.health+=self.HealthBonus
AttributeError: Hero instance has no attribute 'HealthBonus'

有人可以帮助我确定此属性错误的原因吗？

Answer 1

您的问题就在这里

>>> class Hero:
     def __init__(self):
         self.health = 100
     def eat (self, food):
         if food == ham:
             print 'Bob has gained health!'
             self.health+=self.HealthBonus
         elif food == poison:
             print 'Oh no! Bob has taken damage!'
             self.health-=self.HealthDown

您具有“ self.HealthBonus”，并且self指向拥有当前所调用方法（函数）的类的实例。 Eat由 Hero 类拥有。当您将 food 变量传递给eat方法时，Food是具有健康加成的东西，而不是Hero。更改为此：

>>> class Hero:
     def __init__(self):
         self.health = 100
     def eat (self, food):
         if food == ham:
             print 'Bob has gained health!'
             self.health+=food.HealthBonus
         elif food == poison:
             print 'Oh no! Bob has taken damage!'
             self.health-=food.HealthDown

了解类以及导致此属性错误的原因

1 个答案: