text: import pygame
  from pygame.sprite import Sprite
  
  class Alien(Sprite):
      """Class for alien description"""
      def __init__(self, game_settings, screen):
          """Create alien object and define its start position"""
          super().__init__()
          self.screen = screen
          self.game_settings = game_settings
          # load alien image and set rect atribute
          self.image = pygame.image.load("images/vaenlanevaike.bmp")
          self.rect = self.image.get_rect()
          self.rect.x = self.rect.width
          self.rect.y = self.rect.height
          # set alien position
          self.x = float(self.rect.x)
      def blitme(self):
          """Draw alien at his position"""
          self.screen.blit(self.image, self.rect)
      def update(self):
          """Update alien position to right or left"""
          self.x += self.game_settings.alien_speed_factor * self.game_settings.fleet_direction
          self.rect.x = self.x
      def check_edges(self):
          screen_rect = self.screen.get_rect()
          if self.rect.right >= screen_rect.right:
              return True
          elif self.rect.left <= 0:
              return True