弱弱的问下，用python怎么编写乒乓球类小游戏

import sys, pygame
from random import *
from pygame.locals import *
from pygame.font import *
class MyPlayer(pygame.sprite.Sprite):
    def __init__(self, image_file, location, speed):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load(image_file)
        self.rect = self.image.get_rect()
        self.rect.left, self.rect.top = location
        self.speed = speed
        self.status = True
    def move(self):
        self.rect = self.rect.move(self.speed)
        if self.rect.left < 0 or self.rect.right > width:
            self.speed[0] = -self.speed[0]
        if self.rect.top < 0: 
            self.speed[1] = -self.speed[1]
        if self.rect.bottom > height:
            #Game over
            self.status = False
class Reflector(pygame.sprite.Sprite):
    def __init__(self, image_file, location, speed):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load(image_file)
        self.rect = self.image.get_rect()
        self.rect.left, self.rect.top = location
        self.speed = speed
    def move(self):
        self.rect = self.rect.move(self.speed)
        if self.rect.left < 0 or self.rect.right > width:
            self.speed[0] = -self.speed[0]
        if self.rect.top < 0 or self.rect.bottom > height:
            self.speed[1] = -self.speed[1]
def animate(players):
    screen.fill([255,255,255])
    for player in players:
        player.move()
    for player in players:    
        players.remove(player)
        if pygame.sprite.spritecollide(player,players,False):
            player.speed[0] = -player.speed[0]
            player.speed[1] = -player.speed[1]
        players.add(player)
        player.move()
        screen.blit(player.image,player.rect)
    pygame.display.flip()
    pygame.time.delay(10)

pygame.init()
size = width,height = 640,480
screen = pygame.display.set_mode(size)
screen.fill([255,255,255])
pygame.display.set_caption("MiaoWa Game")
def play():
    img_player = "C:\Users\dswu\Desktop\player.png"
    players = pygame.sprite.Group()
    for row in range(0,1):
        for column in range(0,1):
            playerLocation = [column*250+10,row*250+10]
            playerSpeed = [choice([-2,2]), choice([-2,2])]
            player = MyPlayer(img_player, playerLocation, playerSpeed)
            players.add(player)
    img_ref_path = "C:\Users\dswu\Desktop\Reflector.png"
    ref_pos = [0,464]
    ref_speed = [0,0]
    reflector = Reflector(img_ref_path, ref_pos, ref_speed)
    players.add(reflector)
    running = True
    while running:
        key_pressed = pygame.key.get_pressed()
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                game.quit()
            if event.type == KEYDOWN:
                if event.key == K_LEFT:  
                    ref_speed[0] = -2
                elif event.key == K_RIGHT:
                    ref_speed[0] = +2
        animate(players)
        if player.status == False:
            running = False
    final_text = "Game Over!"
    ft_font = pygame.font.Font(None, 100)
    ft_surf = ft_font.render(final_text, 1, (0,0,0))
    screen.blit(ft_surf, [screen.get_width()/2 - ft_surf.get_width()/2, 100])
    tip_text = "Type any key to continue"
    tip_font = pygame.font.Font(None, 50)
    tip_surf = tip_font.render(tip_text, 1, (0,0,0))
    screen.blit(tip_surf, [screen.get_width()/2 - tip_surf.get_width()/2, 200])
    pygame.display.flip()
    keepOn = True
    while keepOn:
        key_pressed = pygame.key.get_pressed()
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
            if event.type == KEYDOWN:
                play()
play()