Bounce game, using Python 3 & Tkinter

paddleball.py

from tkinter import *
import random
import time

class Ball:
  def __init__(self, canvas, paddle, color):
		self.canvas = canvas
		self.paddle = paddle

		self.id = canvas.create_oval(10, 10, 25, 25, fill=color)

		starts = [-3, -2, -1, 1, 2, 3]
		random.shuffle(starts)

		self.x = starts[0]
		self.y = -3
		self.canvas_height = canvas.winfo_height()
		self.canvas_width = canvas.winfo_width()

		self.is_hitting_bottom = False

		canvas.move(self.id, 245, 100)

	def draw(self):
		self.canvas.move(self.id, self.x, self.y)

		pos = self.canvas.coords(self.id)

		if pos[1] <= 0:
			self.y = 1

		if pos[3] >= self.canvas_height:
			# self.y = -1
			self.is_hitting_bottom = True

		if self.hit_top_paddle(pos) == True:
			self.y = -3

		if self.hit_bottom_paddle(pos) == True:
			self.y = 1

		if pos[0] <= 0:
			self.x = 3

		if pos[2] >= self.canvas_width:
			self.x = -3

	def hit_top_paddle(self, pos):
		paddle_pos = self.canvas.coords(self.paddle.id)
		if pos[2] >= paddle_pos[0] and pos[0] <= paddle_pos[2]:
			if pos[3] >= paddle_pos[1] and pos[3] <= paddle_pos[3]:
				return True

		return False

	def hit_bottom_paddle(self, pos):
		paddle_pos = self.canvas.coords(self.paddle.id)
		if pos[2] >= paddle_pos[0] and pos[0] <= paddle_pos[2]:
			if pos[1] >= paddle_pos[1] and pos[1] <= paddle_pos[3]:
				return True

		return False

class Paddle:
	def __init__(self, canvas, color):
		self.canvas = canvas
		self.id = canvas.create_rectangle(0, 0, 100, 10, fill=color)

		self.x = 0
		self.canvas_width = canvas.winfo_width()

		canvas.move(self.id, 200, 300)

		canvas.bind_all('<KeyPress-Left>', self.move_left)
		canvas.bind_all('<KeyPress-Right>', self.move_right)

	def draw(self):
		self.canvas.move(self.id, self.x, 0)

		pos = self.canvas.coords(self.id)

		if pos[0] <= 0:
			self.x = 0

		if pos[2] >= self.canvas_width:
			self.x = 0

	def move_left(self, event):
		self.x = -2

	def move_right(self, event):
		self.x = 2

tk = Tk()
tk.title('Game')
canvas = Canvas(tk, width=550, height=400, bd=0, highlightthickness=0)
canvas.pack()
tk.update()

paddle = Paddle(canvas, 'blue')
ball = Ball(canvas, paddle, 'red')

while 1:
	if ball.is_hitting_bottom == False:
		ball.draw()
		paddle.draw()

	tk.update_idletasks()
	tk.update()
	time.sleep(0.01)