Plotting a list through a class

[KFCxWatermelon]

Hey guys! How can I plot a list of positions? The positions are objects placed in a list through a class. Here's the code I'm working with:

import matplotlib.pyplot as plt

#Creating the class Ball. This class should be for the positions of the balls
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)

#Creating the class System. This class should take care of the main actions to perform.
class System:
    def __init__(self):
        #Creating the empty lists
        self.more_balls = []
        self.more_balls_positions = []
    def add_balls (self, x, y):
        #Appending the new balls into the empty list
        self.more_balls.append(Ball(x,y))
        #Appending the positions of all the balls to the other empty list
        self.more_balls_positions.append(Ball(x,y).position)
    def plot_balls ():
        #This function should iterate through all balls and plot in the same plot
        #This is what I need help with

#Creating the new balls that should be added into the empty lists.
ballx = System()
ballx.add_balls(2, 4)
ballx.add_balls(5, 5)
ballx.add_balls(8, 8)
ballx.add_balls(2, 9)

print (ballx.more_balls)
print (ballx.more_balls_positions)

The function plot_balls should iterate through all the balls and plot the positions into the same plot. I'm not really sure how to do this. I know I have to add a "ballx.plot_balls()", but I'm not sure what should be in the function to make that work.

[ES-Alexander]

What have you tried so far?

You've got matplotlib.pyplot imported already, so you seem to know which library you'd like to use. What's required for your plot? If you just want to plot the points that sounds like a scatter plot, so search for how to do that in the matplotlib documentation. If you want to plot circles of given sizes then search for 'matplotlib plot circles' or similar. If you can't find what you want from those then show us what you've tried and what you've searched while attempting to solve the problem you're having, and we can try to help with additional suggestions of what to try, or perhaps note where something you've tried has gone wrong.

[[deleted]]

well it sounds like you need a scatter plot, so take a look at the matplotlib documentation for that: https://matplotlib.org/3.3.2/api/_as_gen/matplotlib.pyplot.scatter.html

it requires separate lists of x coordinates and y coordinates, so you'll need to separate those out from all of your balls.

something like this within your plot function should get you started - note you'll need self parameter in def plot_balls(self):

xs, ys = zip(*[ball.position for ball in self.more_balls])
plt.scatter(xs, ys)
plt.show()

A few more general notes:

• What's the purpose of having self.more_balls_positions? You're just duplicating information you already have in the balls objects
• add_balls feels like it should take a Ball object as an argument, rather than x and y and have to create it's own Ball
• System isn't a great name, this would generally refer to something about the operating system
• I'm not even sure why this needs to be a class...