Python面向对象编程-三大特性-继承-super() 函数

class Shape:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def area(self):
        pass

class Circle(Shape):
    def __init__(self, x, y, r):
        super().__init__(x, y)
        self.r = r

    def area(self):
        return 3.14 * self.r ** 2

class Square(Shape):
    def __init__(self, x, y, l):
        super().__init__(x, y)
        self.l = l

    def area(self):
        return self.l ** 2

class Rectangle(Shape):
    def __init__(self, x, y, w, h):
        super().__init__(x, y)
        self.w = w
        self.h = h

    def area(self):
        return self.w * self.h

# 创建一个 Circle 对象
c = Circle(0, 0, 2)

# 创建一个 Square 对象
s = Square(0, 0, 2)

# 创建一个 Rectangle 对象
r = Rectangle(0, 0, 2, 3)

# 调用各个对象的 area() 方法
print(c.area())
print(s.area())
print(r.area())