PongTutorial-1

from tkinter import *
import time, random

class Game:
    def __init__(self):
        self.tk = Tk()
        self.tk.title("Pong tutorial")
        self.tk.resizable(0,0)
        self.tk.wm_attributes("-topmost", 1)
        self.canvas = Canvas(self.tk, width=500, height=500)
        self.canvas.pack()
    def mainloop(self):
        while True:
            b.draw()
            self.tk.update()
            time.sleep(0.01)

class Ball:
    def __init__(self, game):
        self.tk = game
        self.id = self.tk.canvas.create_oval(20, 20, 38, 38, fill="red")
        l = [-3, -2, -1, 1, 2, 3]
        x = random.choice(l)
        self.x, self.y = x,-3
    def draw(self):
        self.tk.canvas.move(self.id, self.x, self.y)
        pos = self.tk.canvas.coords(self.id) #[x, y, x1, y1]
        if pos[0] <= 0: #x
            self.x = 3
        elif pos[1] <= 0: #y
            self.y = 3
        elif pos[2] >= 500: #x1
            self.x = -3
        elif pos[3] >= 500: #y1
            self.y = -3

if __name__ == "__main__":
    g = Game()
    b = Ball(g)
    g.mainloop()