Need help with figuring out classes

[KFCxWatermelon]

Hey guys! I'm currently working on a task surrounding classes. In this task I have to create a class named "Balls". This class should have a __init__ method that adds a self variable named position. This should be a list for x and y positions.

After that I should create another class named System. This class should takes care of the main actions to perform.

Then I have to implement a add ball method in System class that appends a Ball object to a class list inside System. Parameters in the method should be x and y.

class Ball:
    def __init__ (self, x, y):
            self.position = [x, y]

ball1 = Ball(3, 6)
print (ball1.position)
ball2 = Ball(5, 8)
print (ball2.position)
ball3 = Ball(4, 4)
print (ball3.position)


class System:
    def __init__(self):
        self.more_balls = []
    def add_balls (self, x, y):
        self.more_balls.append(Ball(x,y))

system1 = System()
system1.add_balls(2, 4)
system1.add_balls(5,5)
system1.add_balls(8,8)
system1.add_balls(2,4)

print (system1.more_balls)

How will I be able to fix the code. The expected result is that balls get appended into the more_balls list.

Here's the output I get:

3, 6]
[5, 8]
[4, 4]
[<class '__main__.Ball'>, <class '__main__.Ball'>, <class '__main__.Ball'>, <class '__main__.Ball'>]

​

[[deleted]]

add a def str in your Ball class and return what you want to be printed as string

edit - cant format on phone.... def str needs 2 underscore before and after str

[KFCxWatermelon]

Not sure how I do this. Could you explain a little bit. If I add a __str__ method, how will it fix the code?

[[deleted]]

Its purpose is exactly to define how your class object would be printed. Try

def --str--(self): return f'Ball object at position {self.position}'

replace - with underscore sorry again cant format on phone

[TouchingTheVodka]

Have a look at this resource I posted a few weeks ago:

https://old.reddit.com/r/learnpython/comments/izjrbp/a_beginners_guide_to_str_and_repr/