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是否可以在python3中设置基本合成实例的属性？

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所以，我一直在阅读Python中的组合，我想知道是否有一种方法来集成设置“基础对象”属性而不特别指向“基类”（如下面代码的注释部分所做的那样） .

所以，我正在寻找下面剪切的代码来打印：

1
2    
3    
4
Success

但是，通过这个片段，我生成了一个RecursionError .

是否有一种方法（self.a.x = n除外）更新A类的属性，以便与其他组合类共享（本例中为C类）？

class A:
    def __init__(self):
        self.x = 1

class B:
    def __init__(self, a):
        self.a = a
        self.y = 2
        print(self.x)
        print(self.y)
        self.x = 3  
        # would work if "self.a.x = 3"
        # and "__setattr__" commented out

    def __getattr__(self, attr):
        return getattr(self.a, attr)

    # setattr would have to be commented out here too
    def __setattr__(self, attr, val):
        setattr(self.a, attr, val)

class C:
    def __init__(self, a):
        self.a = a
        print(self.x)
        self.x = 4
        print(self.x)
        try:
            print(self.y)
        except AttributeError:
            print('Sucess')

    def __getattr__(self, attr):
        return getattr(self.a, attr)

    def __setattr__(self, attr, val):
        setattr(self.a, attr, val)

a = A()
b = B(a)
c = C(a)
python python-3.x oop composition

1 回答

  • 0

    这是可能的，但您需要过滤掉该变量 .

    class A:
    def __init__(self):
        self.x = 1

class B:
    def __init__(self, a):
        self.a = a
        self.x = 2
        self.y = 3  

    def __getattr__(self, attr):
        return getattr(self.a, attr)

    # setattr would have to be commented out here too
    def __setattr__(self, attr, val):
        if attr != "a":
            setattr(self.a, attr, val)
        else:
            super().__setattr__(attr, val)

a = A()
b = B(a)
print(a.x)
print(a.y)
    回复于

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