Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Python Object-Oriented Python Instant Objects Master Class

Posted by Unashe Mutambashora
Unashe Mutambashora
3,433 Points

increment of number of laps

Any ideas on how I can increase the laps every time the method run_lap is called?

racecar.py 
class RaceCar:



     def __init__(self,color,fuel_remaining,laps = 0,**Kwargs):
        self.color = color
        self.fuel_remaining = fuel_remaining
        self.laps = laps

        for attribute,value in Kwargs.items():
            setattr(self,attribute,value)

    def run_lap(self.length):
        laps = laps + 1
        return fuel_remaining - (length * 0.0125)

3 Answers

boi
boi
14,242 Points
boi
boi
14,242 Points

You have a few problems with your code.

class RaceCar:



     def __init__(self,color,fuel_remaining,laps = 0,**Kwargs):  # 👈 An extra indent (error)
        self.color = color
        self.fuel_remaining = fuel_remaining
        self.laps = laps

        for attribute,value in Kwargs.items():
            setattr(self,attribute,value)

    def run_lap(self.length):  # 👈 Used a period (error)
        laps = laps + 1  # 👈 Incorrect method to increment laps try (self.laps += 1)
        return fuel_remaining - (length * 0.0125)  # 👈 Incorrect method to use fuel_remaining. Also additional 0 in place
                                                  #    Try (self.fuel_remaining -= length * 0.125)

Try to make these changes, and you are golden.

If problems still persists, tag me again by leaving a comment, and I will try to help out.

Unashe Mutambashora
Unashe Mutambashora
3,433 Points

Thanks for your response mate. I tried making those adjustments and still I am getting it wrong

class RaceCar: laps = 0

def __init__ (self,color,fuel_remaining,**kwargs):
    self.color = color
    self.fuel_remaining = fuel_remaining


    for attribute,value in kwargs.items():
        setattr(self,attribute,value)

def run_laps(self,length):
    self.laps+=1
    return self.fuel_remaining-=length * 0.125
boi
boi
14,242 Points
boi
boi
14,242 Points 
class RaceCar:

    def __init__ (self,color,fuel_remaining,**kwargs):
        self.color = color
        self.fuel_remaining = fuel_remaining
        self.laps = 0


        for attribute,value in kwargs.items():
            setattr(self,attribute,value)

    def run_laps(self,length):
        self.laps+=1
        self.fuel_remaining -= length * 0.125  👈 # no need to use return
Unashe Mutambashora
Unashe Mutambashora
3,433 Points
Unashe Mutambashora
Unashe Mutambashora
3,433 Points

Thanks. that was really helpful

Marion Lackie
Marion Lackie
1,753 Points

Hi boi, this was really helpful. What I don't quite understand is why laps isn't set as an argument in the first line of the def_init_ method, along with the color and fuel_remaining arguments. I suspect this highlights my incomplete understanding of creating methods!!

boi
boi
14,242 Points
boi
boi
14,242 Points

The self.laps argument should not be altered with, the self.laps argument is a starting value and should be away from the user, suppose if we have set the self.laps argument 👇

class RaceCar:

    def __init__ (self, color, fuel_remaining, laps = 0, **kwargs):
        self.color = color
        self.fuel_remaining = fuel_remaining
        self.laps = laps


        for attribute,value in kwargs.items():
            setattr(self,attribute,value)


    def run_laps(self,length):
        self.laps+=1
        self.fuel_remaining -= length * 0.125

Now the self.laps argument can be set to anything, it would make no sense because the self.laps attribute is like a condition, it will increase by default only if the run_laps method is used.

Some attributes should be set behind the scenes, so it can be default or constant, that value should not be changed.

Note: In the above example even if the self.laps argument is not given, it still can be changed by the user 👇

 class RaceCar:

    def __init__ (self, color, fuel_remaining, **kwargs):
        self.color = color
        self.fuel_remaining = fuel_remaining
        self.laps = 0


        for attribute,value in kwargs.items():
            setattr(self,attribute,value)


    def run_laps(self,length):
        self.laps+=1
        self.fuel_remaining -= length * 0.125

>>> car = RaceCar("blue", 45, laps = 100)

>>> car.laps
100

This is because of the for_loop setattr, to avoid this make these changes 👇

class RaceCar:

    def __init__ (self, color, fuel_remaining, **kwargs):
        self.color = color
        self.fuel_remaining = fuel_remaining

        for attribute,value in kwargs.items():
            setattr(self,attribute,value)

        self.laps = 0 👈 #Set (self.laps) after the for loop

    def run_laps(self,length):
        self.laps+=1
        self.fuel_remaining -= length * 0.125

>>> car = RaceCar("blue", 45, laps = 100)

>>> car.laps
0

Tag me if you need more help.

Marion Lackie
Marion Lackie
1,753 Points
Marion Lackie
Marion Lackie
1,753 Points

Nice!
That makes more sense to me now. Thanks for the detailed response :)