How to format the docstring for inherited methods in python?

Question

I have the following objects, in cars.py

import abc

class Car(abc.ABC):

  def drive(self):
    """This is the docstring for how to drive a {0}."""
    pass

class Van(Car):

  def shut_sliding_door(self):
    pass

class Hybrid(Car):

  def plug_in(self):
    pass

Van.drive.__doc__ = Car.drive.__doc__.format('van')
Hybrid.drive.__doc__ = Car.drive.__doc__.format('hybrid')

However, the docstring for Hybrid.drive is formatted with the "van" string rather than the "hybrid" string.

import cars as cars

cars.Hybrid.drive.__doc__
> "This is the docstring for how to drive a van."

cars.Van.drive.__doc__
> "This is the docstring for how to drive a van."

It appears that the line Van.drive.__doc__ = Car.drive.__doc__.format('van') is changing the string Car.drive.__doc__.format('van'). This is confirmed with,

cars.Car.drive.__doc__
> "This is the docstring for how to drive a van."

How do I format the string for Hybrid.drive.__doc__ so that it is "This is the docstring for how to drive a hybrid"?

Edit:

Although overriding the drive method in the children classes can work, what if drive is a long method and all I want to change about it in the children classes are the docstring?

Answer 1

That is because you did not override the method in the children class. So at the very first, if you call Hybrid.drive that is the exact same method as Car.drive, there is only one method existing no matter the class you access it from

If you override them, you'll get different method, each one has its own and so its own docstring

class Car(abc.ABC):
    def drive(self):
        """This is the docstring for how to drive a {0}."""
        pass

class Van(Car):
    def shut_sliding_door(self):
        pass
    def drive(self):
        pass

class Hybrid(Car):
    def plug_in(self):
        pass
    def drive(self):
        pass

if __name__ == '__main__':
    Van.drive.__doc__    = Car.drive.__doc__.format('van')
    Hybrid.drive.__doc__ = Car.drive.__doc__.format('hybrid')

    print(Van.drive.__doc__)     # This is the docstring for how to drive a van.
    print(Hybrid.drive.__doc__)  # This is the docstring for how to drive a hybrid.
    print(Car.drive.__doc__)     # This is the docstring for how to drive a {0}.