why a method from my subclass not working

January 28, 2022

Here’s me playing around with super() method:

class Rectangle:

    def __init__(self, width, length):

        self.width = width
        self.length = length

    def perimeter(self):

        fvalue = (self.width * 2) + (self.length * 2)

        return fvalue

    def area(self):

        fvalue = self.width * self.length

        return fvalue


class Square(Rectangle):

    def __init__(self, width, length):

        super().__init__(width, length)
    
    
    def perimeter(self):

        return super().perimeter(self)

    def area(self):

        return super().area(self)


square = Square(width=3, length=3)
print(square.area())

now when if I run this code I will get an error that said

TypeError: area() takes 1 positional argument but 2 were given

which is weird because in Square.area() I’ve only passed 1 argument to the super.area() method.
I later removed that argument and the code works fine, but I’m still confused as of why this error had happened because in Square.__init__() I need to pass an argument for it to work. An explanation to this will be appreciated

>Solution :

You don’t need the methods in Square that duplicate the methods in the parent class. This will work fine:

class Rectangle:

    def __init__(self, width, length):
        self.width = width
        self.length = length

    def perimeter(self):
        fvalue = (self.width * 2) + (self.length * 2)
        return fvalue

    def area(self):
        fvalue = self.width * self.length
        return fvalue


class Square(Rectangle):

    def __init__(self, width, length):
        super().__init__(width, length)
    

square = Square(width=3, length=3)
print(square.area())