Python:

Create a Car class that has the following characteristics:

It has a gas_level attribute.

It has a constructor (__init__ method) that takes a float representing the initial gas level and sets the gas level of the car to this value.

It has an add_gas method that takes a single float value and adds this amount to the current value of the gas_level attribute.

It has a fill_up method that sets the cars gas level up to 13.0 by adding the amount of gas necessary to reach this level. It will return a float of the amount of gas that had to be added to the car to get the gas level up to 13.0. However, if the cars gas level was greater than or equal to 13.0 to begin with, then it doesnt need to add anything and it simply returns a 0.

(Note: you can call the add_gas method from within the fill_up method by using this syntax: self.add_gas(amount).)

Heres an example.

example_car = Car(9) print(example_car.fill_up()) # should print 4 another_car = Car(18) print(another_car.fill_up()) # should print 0 

Reminder: Dont forget about the self parameter! 

from test import testEqual testEqual( Car(10).fill_up(), 3 ) testEqual( Car(20).fill_up(), 0 ) testEqual( Car(5.5).fill_up(), 7.5 ) testEqual( Car(12.5).fill_up(), 0.5 ) testEqual( Car(13).fill_up(), 0 )