Заготовка для пинг-понга

from tkinter import*
from random import *
from time import *

class Ball:
    def __init__(self, canvas, color):
        self.canvas = canvas
        self.id = canvas.create_oval(10,10,25,25,fill=color)
        self.canvas.move(self.id, 225, 180)
        starts = [-3, -2, -1, 1, 2, 3]
        shuffle(starts)
        self.x = choice(starts)
        self.y = choice(starts)

    def draw(self):
        self.canvas.move(self.id, self.x, self.y)
        (x1, y1, x2, y2) = self.canvas.coords(self.id)
        if x2 >= self.canvas.winfo_width() or x1 <= 0:
            self.x *= -1
        if y2 >= self.canvas.winfo_height() or y1 <= 0:
            self.y *= -1

root = Tk()
root.title('Пинг-понг')
canvas = Canvas(width = 500, height = 400, bg = 'deepskyblue')
canvas.pack()

balls = []
for i in range(100):
    R = '%02x'%randint(0,255)
    G = '%02x'%randint(0,255)
    B = '%02x'%randint(0,255)
    color = '#'+R+G+B
    ball = Ball(canvas, color)
    balls.append(ball)

while True:
    for ball in balls:
        ball.draw()
    root.update_idletasks()
    root.update()
    sleep(0.01)