alien we initially place each alien near the top-left corner of the screenadding space to the left of it that' equal to the alien' width and space above it equal to its height creating an instance of the alien now we create an instance of alien in alien_invasion pyalien_ invasion py --snip-from ship import ship from alien import alien import game_functions as gf def run_game()--snip-make an alien alien alien(ai_settingsscreenstart the main loop for the game while truegf check_events(ai_settingsscreenshipbulletsship update(gf update_bullets(bulletsgf update_screen(ai_settingsscreenshipalienbulletsrun_game(here we're importing the new alien class and creating an instance of alien just before entering the main while loop because we're not changing the alien' position yetwe aren' adding anything new inside the loophoweverwe do modify the call to update_screen(to pass it the alien instance making the alien appear onscreen to make the alien appear onscreenwe call its blitme(method in update_screen()game_ functions py def update_screen(ai_settingsscreenshipalienbullets)--snip-redraw all bullets behind ship and aliens for bullet in bulletsbullet draw_bullet(ship blitme(alien blitme(make the most recently drawn screen visible pygame display flip(