Question

I have the following code.py file:

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

    def move(self, delta_x, delta_y):
        self.x += delta_x
        self.y += delta_y

class Square(Shape):
    def __init__(self, side=1, x=0, y=0):
        super().__init__(x, y)
        self.side = side

class Circle(Shape):
    def __init__(self, rad=1, x=0, y=0):
        super().__init__(x, y)
        self.radius = rad

I’m running the code in the Python interpreter like this:

>>> import code
>>> c = code.Circle(1)

I’m getting this error:

Traceback (most recent call last):<br>
...<br>
File "code.py", line 18, in __init__<br>
super().__init__(x, y)<br>
TypeError: super() takes at least 1 argument (0 given)<br>

I don’t understand why I’m getting this error. I’m specifying a rad value of 1 and I would assume that since I didn’t specify x and y values, Circle should be using the default values of x=0 and y=0 and passing them to Shape via the super() function. What am I missing?

BTW, I’m using Python 2.7.1.

Thanks.

Answer 1

super requires an argument and this is exactly what the error message is saying. In your case you need to use super(Circle, self) and super(Square, self).

For the gory details you can see this SO question or you can just check the official documentation.

Note that unless you want to do funny things the code can be simplified in

Shape.__init__(self, x, y)

in both cases. Until you understand super and why it can be useful I would suggest to simply stay away from it. You can live an happy life as a productive Python programmer without touching that.