如何仅从 Python 中的超级 class 继承一些变量

Question

I am trying to make a subclass, Square, from a superclass, Shape.

class Shape :

     def __init__ (self, x, y) :
          self.x = x
          self.y = y
          self.description = "This shape has not been described yet"
      
     def area (self) :
          return self.x * self.y

     def describe (self, text) :
          self.description = text

I have tried

class Square (Shape) :

     def __init__ (self, x) :
          self.x = x
          self.y = x
          self.description = "This shape has not been described yet"

which seems to work, but the only thing that actually changes in Square is self.y = x, so I wonder if I could do the same thing without having to write self.x and self.description again.

(I tried doing something like this:

class Square (Shape) :

     def __init__ (self, x) :
          self.y = x
          super().__init__()

but, when I create a Square object, a type error occurs: TypeError: init () missing 2 required positional arguments: 'x' and 'y')

Answer 1

A Square is a Shape whose x and y are the same. Hence:

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

You just need to call Shape.__init__(self, x, y) with your x as both the x and y parameters.

Answer 2

Just call the super function inside __init__ . Put both the arguments equal to x .

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