VPython Lists

Yu Zhou Fall 2025 An introduction to creating and using lists in VPython.

The Main Idea

Let's say you want to create 100 or maybe even 12,000 tennis balls to help you stop a 17, 500 kg block of mass sliding right at you using VPython. Now, you could perhaps do it like this:

ball1 = sphere(color=color.blue, radius=0.2)
ball2 = sphere(color=color.blue, radius=0.2)
ball3 = sphere(color=color.blue, radius=0.2)
ball4 = sphere(color=color.blue, radius=0.2)
ball5 = sphere(color=color.blue, radius=0.2)

and so on and so on. However, this can get really disorganized, and you probably don't want to count all the way to 'ball12000'. Fortunately, we can use lists to contain all of these balls!

ball_list = []

num_balls = 1000

for i in range(num_balls):
    pos = vector(0, 0, i)
    radius = 1
    ball = sphere(pos=pos, radius=radius, color=color.red)
    
    ball_list.append(ball)

Now that's a lot of balls.