The player sprite class

player.py

class Player(pygame.sprite.Sprite):
  def __init__(self, sprites):
    super(Player, self).__init__()
    self.timer = 0
    self.interval = 2
    self.number_of_images = 6
    self.images = sprites.load_strip([0, 130, 48, 45], self.number_of_images, -1)
    self.surf = self.images[0]
    self.rect = self.surf.get_rect(center=(constants.SCREEN_WIDTH / 2, constants.SCREEN_HEIGHT - 40))
    self.image_index = 0

  def get_event(self, event):
    pass

  def update(self, pressed_keys):
    self.timer += 1

    if pressed_keys[K_LEFT]:
      self.rect.move_ip(-5, 0)
    if pressed_keys[K_RIGHT]:
      self.rect.move_ip(5, 0)

    if self.rect.left < 0:
      self.rect.left = 0
    if self.rect.right > constants.SCREEN_WIDTH:
      self.rect.right = constants.SCREEN_WIDTH

  def get_surf(self):
    if self.timer % self.interval == 0:
      self.image_index += 1
      if self.image_index >= self.number_of_images:
        self.image_index = 0
    return self.images[self.image_index]