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Python Object-Oriented Python Instant Objects Master Class

Posted by Alan T.
Alan T.
4,784 Points

Classes. What's wrong?

I've tried a few things and can't seem to figure out what's wrong with my beginner code. If someone can point me towards the right direction that would be great, thank you.

Vrroom!

OK, now let's add a method named run_lap. It'll take a length argument. It should reduce the fuel_remaining attribute by length multiplied by 0.125.

Oh, and add a laps attribute to the class, set to 0, and increment it each time the run_lap method is called.

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(self, length):
        self.laps += 1
        new = length * 0.125
        return self.fuel_remaining - self.new

1 Answer

Pedro Cabral
Pedro Cabral
33,586 Points

A couple of issues:

  1. You are declaring the variable new as a local variable but then you are calling it with self.new which doesn't exist. Your variable being local, only exists within the block of code it was created, so if you want to access it, drop the self. bit;
  2. You are doing the math to reduce the fuel_remaining but the result of that calculation should be assigned to the variable fuel_remaining so that you indeed reduce it. You can do this one of two ways: foo -= bar or foo = foo - bar;
  3. There's no need to return the result of the calculation at the end of the method;