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


class?Ball:
????def?__init__（self?canvas?paddle?score?color）:
????????self.canvas?=?canvas
????????self.paddle?=?paddle
????????self.score?=?score
????????self.id?=?canvas.create_oval（10?10?25?25?fill=color）
????????self.canvas.move（self.id?245?100）
????????starts?=?[-3?-2?-1?1?2?3]
????????random.shuffle（starts）
????????self.x?=?starts[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）
????????if?pos[1]?<=?0:
????????????self.y?=?1
????????if?pos[3]?>=?self.canvas_height:
????????????self.y?=?-1
????????if?pos[3]?>=?self.canvas_height:
????????????self.hit_bottom?=?True
????????if?self.hit_paddle（pos）:
????????????self.y?=?-3
????????if?pos[0]?<=?0:
????????????self.