text: import pygame
  import random
   
  # Define some colors
  BLACK = (0, 0, 0)
  WHITE = (255, 255, 255)
  RED = (255, 0, 0)
   
   
  class Block(pygame.sprite.Sprite):
      """
      This class represents the ball
      It derives from the "Sprite" class in Pygame
      """
   
      def __init__(self, color, width, height):
          """ Constructor. Pass in the color of the block,
          and its x and y position. """
          # Call the parent class (Sprite) constructor
          super().__init__()
   
          # Create an image of the block, and fill it with a color.
          # This could also be an image loaded from the disk.
          self.image = pygame.Surface([width, height])
          self.image.fill(color)
   
          # Fetch the rectangle object that has the dimensions of the image
          # image.
          # Update the position of this object by setting the values
          # of rect.x and rect.y
          self.rect = self.image.get_rect()
   
          # Instance variables that control the edges of where we bounce
          self.left_boundary = 0
          self.right_boundary = 0
          self.top_boundary = 0
          self.bottom_boundary = 0
   
          # Instance variables for our current speed and direction
          self.change_x = 0
          self.change_y = 0
   
      def update(self):
          """ Called each frame. """
          self.rect.x += self.change_x
          self.rect.y += self.change_y
   
          if self.rect.right >= self.right_boundary or self.rect.left <= self.left_boundary:
              self.change_x *= -1
   
          if self.rect.bottom >= self.bottom_boundary or self.rect.top <= self.top_boundary:
              self.change_y *= -1
   
   
  class Player(Block):
      """ The player class derives from Block, but overrides the 'update'
      functionality with new a movement function that will move the block
      with the mouse. """
      def update(self):
          # Get the current mouse position. This returns the position
          # as a list of two numbers.
          pos = pygame.mouse.get_pos()
   
          # Fetch the x and y out of the list,
          # just like we'd fetch letters out of a string.
          # Set the player object to the mouse location
          self.rect.x = pos[0]
          self.rect.y = pos[1]
   
  # Initialize Pygame
  pygame.init()
   
  # Set the height and width of the screen
  screen_width = 700
  screen_height = 400
  screen = pygame.display.set_mode([screen_width, screen_height])
   
  # This is a list of 'sprites.' Each block in the program is
  # added to this list. The list is managed by a class called 'Group.'
  block_list = pygame.sprite.Group()
   
  # This is a list of every sprite. All blocks and the player block as well.
  all_sprites_list = pygame.sprite.Group()
   
  for i in range(50):
      # This represents a block
      block = Block(BLACK, 20, 15)
   
      # Set a random location for the block
      block.rect.x = random.randrange(screen_width)
      block.rect.y = random.randrange(screen_height)
   
      block.change_x = random.randrange(-3, 4)
      block.change_y = random.randrange(-3, 4)
      block.left_boundary = 0
      block.top_boundary = 0
      block.right_boundary = screen_width
      block.bottom_boundary = screen_height
   
      # Add the block to the list of objects
      block_list.add(block)
      all_sprites_list.add(block)
   
  # Create a red player block
  player = Player(RED, 20, 15)
  all_sprites_list.add(player)
   
  # Loop until the user clicks the close button.
  done = False
   
  # Used to manage how fast the screen updates
  clock = pygame.time.Clock()
   
  score = 0
   
  # -------- Main Program Loop -----------
  while not done:
      for event in pygame.event.get():
          if event.type == pygame.QUIT:
              done = True
   
      # Clear the screen
      screen.fill(WHITE)
   
      # Calls update() method on every sprite in the list
      all_sprites_list.update()
   
      # See if the player block has collided with anything.
      blocks_hit_list = pygame.sprite.spritecollide(player, block_list, True)
   
      # Check the list of collisions.
      for block in blocks_hit_list:
          score += 1
          print(score)
   
      # Draw all the spites
      all_sprites_list.draw(screen)
   
      # Limit to 60 frames per second
      clock.tick(60)
   
      # Go ahead and update the screen with what we've drawn.
      pygame.display.flip()
   
  pygame.quit()