Python:用减法/加法构造类

Question

我试图从双亲生成一个子类，这个类是作为它的和/减构建的。我将试着用一个简单的例子最好地解释。

图为我有以下父类。

class UpperBody():
    
    def __init__(self, owner='John', age=25, max_lifting_weight=100):
        self.owner=owner # Identifier, who "owns" this upper body
        self.age=age # Second identifier
        self.max_lifting_weight=max_lifting_weight
    
    def __add__(self, other):
        #__sub__ would be equivalent
        if other.age!=self.age:
            raise AttributeError('You cannot add body parts with different ages!')
        if other.owner!=self.owner:
            print('This does not seem to fit here, but alright...')
            return UpperBody(self.owner + '_' + other.owner, self.age, self.max_lifting_weight + other.max_lifting_weight)
        
        return UpperBody(self.owner, self.age, self.max_lifting_weight + other.max_lifting_weight)
            
    def can_lift(self, weight):
        # Returns boolean
        return weight < self.max_lifting_weight


class LowerBody():
    
    def __init__(self, owner='John', age=25, max_lifting_weight=100):
        self.owner=owner # Identifier, who "owns" this lower body
        self.age=age # Second identifier
        self.max_lifting_weight=max_lifting_weight
    
    def __add__(self, other):
        #__sub__ would be equivalent
        if other.age!=self.age:
            raise AttributeError('You cannot add body parts with different ages!')
        if other.owner!=self.owner:
            print('This does not seem to fit here, but alright...')
            return UpperBody(self.owner + '_' + other.owner, self.age, self.max_lifting_weight + other.max_lifting_weight)
        
        return UpperBody(self.owner, self.age, self.max_lifting_weight + other.max_lifting_weight)
            
    def can_lift(self, weight):
        # Legs are stronger
        return weight < self.max_lifting_weight * 1.2

我想通过来生成Human子类，添加这两个父类。这样的东西，

class Human(UpperBody, LowerBody):
    
    def __init__(self, name, age, max_lifting_weight_upper, max_lifting_weight_lower):
        self.name=name
        self.age=age
        # From here on, I have no clue how to follow. This does not load to "self", obviously.
        UpperBody.__init__(name, age, max_lifting_weight_upper) + LowerBody.__init__(name, age, max_lifting_weight_upper)

以及稍后访问在父类中定义的方法(如can_lift )。

我能想到的最好的方法就是通过一个函数，

def HumanConstructor(UpperBody, LowerBody):
    return UpperBody + LowerBody

但是，如果Human有额外的方法，这将不会有太大的帮助。有办法这样做吗？

事先谢谢！

Answer 1

基本上，您只需要正确地初始化Human中的子类：

class Human(UpperBody, LowerBody):
    
    def __init__(self, name, age, max_lifting_weight_upper, max_lifting_weight_lower):
        self.name=name
        self.age=age

        # create the child class instances
        UpperBody.__init__(name, age, max_lifting_weight_upper)
        LowerBody.__init__(name, age, max_lifting_weight_upper)

    def do_something(self):
        UpperBody.can_lift()
        LowerBody.can_lift()