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Python Object-Oriented Python Instant Objects Master Class

Michael Crowley
Michael Crowley
1,352 Points
Posted by Michael Crowley
Michael Crowley
1,352 Points

Object-Oriented Python: Master Class Challenge Task 2

Hello All,

I'm having trouble figuring out the issue with my code below; receiving an error "Bummer: Try again!" but not much detail outside of that.

I've tried manipulating the run_lap function a few different ways:

  • Using fuel_remaining instead of self.fuel_remaining
  • Returning the value of fuel_remaining
  • Using self.laps instead of laps

I haven't had any luck with these. Any insight would be much appreciated!

Thank you!

racecar.py 
class RaceCar:
    laps = 0

    def __init__(self, color, fuel_remaining, **kwargs):
        self.color = color
        self.fuel_remaining = fuel_remaining
        for key, value in kwargs.items():
            setattr(self, key, value)

    def run_lap(length):
        self.fuel_remaining -= (length * 0.125)
        laps += 1
Michael Crowley
Michael Crowley
1,352 Points
Michael Crowley
Michael Crowley
1,352 Points

Challenge Prompt: Vrroom!

OK, now let's handle the racecar running laps. Add a laps attribute to the RaceCar class and set it to 0. Add a method named run_lap. It'll take a length argument. It should reduce the fuel_remaining attribute by the length argument multiplied by 0.125 (length * 0.125). Also, increment the laps attribute by 1 each time the run_lap method is called.

1 Answer

Julian Addison
Julian Addison
13,302 Points
Julian Addison
Julian Addison
13,302 Points

So, you've basically solved the challenge, the one mistake is the scope of the laps attribute. Within your run_lap method, you just have to make sure to reference the self keyword. Otherwise, when you try to run the method, python will think that you are creating a new local variable laps and you'll get an error like UnboundLocalError: local variable 'laps' referenced before assignment.

self.laps += 1