Simple animation sketch for p5 python

animation.py

from p5 import *
import random

width = 1280
height = 720
circle_count = 400
circles = []

def setup():
    size(width, height)
    no_stroke()   
    for _ in range(circle_count):
        pos = Vector(random.uniform(0, width), random.uniform(0, height))
        vel = Vector(random.uniform(-1.0, 1.0), random.uniform(-1.0, 1.0))
        diameter = random.uniform(2, 32)
        color = Color(random.uniform(0, 255), 
                      random.uniform(0, 255), 
                      random.uniform(0, 255), 190)
        circles.append({'pos': pos, 'vel': vel, 'diameter': diameter, 'color': color})
        
def draw():
    fill(0, 30)
    rect((0, 0), width, height)
    for c in circles:
        fill(c["color"])
        c["pos"] += c["vel"]
        if c["pos"].x > width or c["pos"].x < 0:
            c["vel"].x *= -1
        if c["pos"].y > height or c["pos"].y < 0:
            c["vel"].y *= -1
        circle((c["pos"].x, c["pos"].y), c["diameter"])

run(renderer='skia')