from Tkinter import *import randomimport timeclass Ball:  def __init__(self, canvas, paddle, color):    self.canvas = canvas    self.paddle = paddle    self.id = canvas.create_oval(10, 10, 25, 25, fill=color)    self.canvas.move(self.id, 245, 100)    startx = [-3, -2, -1, 1, 2, 3]    random.shuffle(startx)    self.x = startx[0]    self.y = -3    self.canvas_height = self.canvas.winfo_height()    self.canvas_width = self.canvas.winfo_width()    self.hit_bottom = False  def draw(self):    self.canvas.move(self.id, self.x, self.y)    pos = self.canvas.coords(self.id)#top-left bottom-right    if (pos[1] <= 0 or self.hit_paddle(pos) == True):      self.y = -self.y    if (pos[0] <= 0 or pos[2] >= self.canvas_width):      self.x = -self.x    if (pos[3] >= self.canvas_height):      self.hit_bottom = True  def hit_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 Falseclass 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.move(self.id, 200, 300)    self.canvas_width = self.canvas.winfo_width()    self.canvas.bind_all("<Key-Left>", self.turn_left)    self.canvas.bind_all("<Key-Right>", self.turn_right)  def draw(self):    pos = self.canvas.coords(self.id)    if (pos[0] + self.x >= 0 and pos[2] + self.x <= self.canvas_width):      self.canvas.move(self.id, self.x, 0)    #self.x = 0  def turn_left(self, event):    self.x = -4  def turn_right(self, event):    self.x = 4tk = Tk()tk.title("Game")tk.resizable(0, 0)#not resizabletk.wm_attributes("-topmost", 1)#at topcanvas = Canvas(tk, width = 500, height = 500, bd = 0, highlightthickness = 0)canvas.pack()tk.update()#initpaddle = Paddle(canvas, 'blue')ball = Ball(canvas, paddle, 'red')while 1:  if (ball.hit_bottom == False):    ball.draw()    paddle.draw()  tk.update_idletasks()  tk.update()  time.sleep(0.01)