game_ functions py def update_screen(ai_settingsscreenshipaliensbullets)--snip-ship blitme(aliens draw(screenmake the most recently drawn screen visible pygame display flip(when you call draw(on grouppygame automatically draws each element in the group at the position defined by its rect attribute in this casealiens draw(screendraws each alien in the group to the screen creating the fleet now we can create the fleet here' the new function create_fleet()which we place at the end of game_functions py we also need to import the alien classso make sure you add an import statement at the top of the filegame_ functions py --snip-from bullet import bullet from alien import alien --snip-def create_fleet(ai_settingsscreenaliens)"""create full fleet of aliens ""create an alien and find the number of aliens in row spacing between each alien is equal to one alien width alien alien(ai_settingsscreenv alien_width alien rect width available_space_x ai_settings screen_width alien_width number_aliens_x int(available_space_x ( alien_width) create the first row of aliens for alien_number in range(number_aliens_x)create an alien and place it in the row alien alien(ai_settingsscreenalien alien_width alien_width alien_number alien rect alien aliens add(alienwe've already thought through most of this code we need to know the alien' width and height in order to place aliensso we create an alien at before we perform calculations this alien won' be part of the fleetso don' add it to the group aliens at we get the alien' width from its rect attribute and store this value in alien_width so we don' have to keep working through the rect attribute at we calculate the horizontal space available for aliens and the number of aliens that can fit into that space the only change here from our original formulas is that we're using int(to ensure we end up with an integer number of aliens because we don' want to create partial aliensand the range(function needs an aliens