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Python Object-Oriented Python Instant Objects Master Class

rokas stasiulaitis
rokas stasiulaitis
617 Points
Posted by rokas stasiulaitis
rokas stasiulaitis
617 Points

Problem with incrementation

I presume the problem arises with 'increment it each time the run_lap method is called.' Anyone have an idea on what I've done wrong?

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.fuel_remaining = fuel_remaining - (length * 0.125)
        self.laps = laps + 1

1 Answer

Steven Parker
Steven Parker
231,261 Points
Steven Parker
Steven Parker
231,261 Points

It looks like you forgot to use the "self." prefix on the right side of the assignments.

You can make your code more compact and also avoid the potential for this error by using the addition assignment operator (or subtraction assignment), For example:

        self.laps += 1
rokas stasiulaitis
rokas stasiulaitis
617 Points
rokas stasiulaitis
rokas stasiulaitis
617 Points

Thank you for your time, what is the logic behind also referencing "self" on the right side?

Steven Parker
Steven Parker
231,261 Points
Steven Parker
Steven Parker
231,261 Points

That's the only way to access the instance variable. Without it, you're trying to reference a local (or global) variable with that name (and there isn't one).