Normal methods should have at least one parameter and the first parameter should be called self. This makes the purpose of the parameter clear to other developers.

If there is at least one parameter, then change the name of the first parameter to self as recommended by the style guidelines in PEP 8.

If there are no parameters, then it cannot be a normal method. It may need to be marked as a staticmethod or it could be moved out of the class as a normal function.

The following methods can both be used to assign values to variables in a point object. The second method makes the association clearer because the self parameter is used.

Python PEP 8: Function and method arguments.

Python Tutorial: Classes.