bouncing balls (class)

# Copyright (c) 2020 daddygongon
# Released under the MIT license
# https://opensource.org/licenses/mit-license.php
import tkinter as tk
import random
speed = 1
size = 10


class Ball:
    global speed

    def __init__(self, x, y, dx, dy, color):
        self.x, self.y = x, y
        self.dx, self.dy = dx*speed, dy*speed
        self.color = color
        self.shape = None

    def move(self, canvas):
        self.erase(canvas)
        self.x += self.dx
        self.y += self.dy
        self.draw(canvas)
        if (self.x >= canvas.winfo_width() or self.x <= 0):
            self.dx = -self.dx
        if (self.y >= canvas.winfo_height() or self.y <= 0):
            self.dy = -self.dy

    def erase(self, canvas):
        canvas.delete(self.shape)

    def draw(self, canvas):
        self.shape = canvas.create_oval(self.x - size, self.y - size,
                                        self.x + size, self.y + size,
                                        fill=self.color, width=0)


def loop():
    for b in balls:
        b.move(canvas)
    root.after(10, loop)


def color_maker(init, fin):
    color1 = "#"+hex(random.randint(init, fin)
                     ).lstrip("0x")+hex(random.randint(init, fin)
                                        ).lstrip("0x") + hex(random.randint(init, fin)
                                                             ).lstrip("0x")
    return color1


root = tk.Tk()
root.geometry("800x600")

canvas = tk.Canvas(root, width=800, height=600, bg=color_maker(1, 2))
canvas.place(x=0, y=0)

balls = []
for j in range(2**8):
    #    balls.append(Ball(random.randint(390, 410), random.randint(290, 310),
    balls.append(Ball(random.randint(0, 800), random.randint(0, 600),
                      random.randint(0, 10)*2-10, random.randint(0, 10)*2-10,
                      color_maker(8, 15)))

root.after(10, loop)
root.mainloop()