text: import random
  import pygame
  
  BLACK = (0, 0, 0)
  
  class Asteroid(pygame.sprite.Sprite):
  
      def __init__(self):
  
          pygame.sprite.Sprite.__init__(self)
  
          self.image = pygame.image.load('images/mid_1.png').convert()
          self.rect = self.image.get_rect()
          self.image.set_colorkey(BLACK)
  
      def update(self):
          self.rect.x -= 2
  
          if self.rect.x <= -35:
              self.rect.y = random.randint(0, 366)
              self.rect.x = 640
  
      def generate_asteroid_list(self, number_of_asteroids):
          pass
  
  pygame.init()
  
  size = (640, 400)
  screen = pygame.display.set_mode(size)
  
  pygame.display.set_caption("spaceshooter")
  
  done = False
  
  clock = pygame.time.Clock()
  
  background_image = pygame.image.load('images/bg_blue.png').convert()
  
  asteroid_list = pygame.sprite.Group()
  
  for i in range(random.randint(6, 13)):
      asteroid = Asteroid()
      asteroid.rect.x = random.randint(640, 1281)
      asteroid.rect.y = random.randrange(0, 365, 50)
      asteroid_list.add(asteroid)
  
  # -------- Main Program Loop -----------
  while not done:
      # --- Main event loop
      for event in pygame.event.get():
          if event.type == pygame.QUIT:
              done = True
  
      screen.blit(background_image, [0, 0])
  
      asteroid_list.draw(screen)
      asteroid_list.update()
  
      pygame.display.flip()
  
      clock.tick(60)
  
  
  pygame.quit()
  