Python，子代无法继承父代函数

我创建了一个python代码，其中Apple是父类，Macbook是子类，我不能从mackbookpro实例中调用background()函数，如下所述。AttributeError: ‘Macbook’ object has no attribute ‘year_established’.

如果我声明 成立年份 不在 __init__ 函数工作正常。

为什么我不能在子组件实例中获取父类构造函数中提到的数据？

class Apple:

    # year_established=1976 --code run successfully if I declare value here  
    # -- but I commented out

    def __init__(self):
        self.year_established=1976

    def background(self):
        return ('it is established in {}'.format(self.year_established))

class Macbook(Apple):

    def __init__(self):
        self.price = 10000

    def productdetails(self):
        return (str(self.price) + self.background())

macbookpro = Macbook()

print(macbookpro.productdetails())

解决方案：

你需要将父类的初始化器调用到子类的初始化器中，就像…一样。

class Apple:
    def __init__(self):
        self.year_established = 1976

    def background(self):
        return ('it is established in {}'.format(self.year_established))


class Macbook(Apple):
    def __init__(self):
        super().__init__()
        self.price = 10000

    def productdetails(self):
        return (str(self.price) + self.background())


macbookpro = Macbook()

print(macbookpro.productdetails())