alien_invasion.py

import sys
import pygame
class AlienInvasion:
    """overall class to manage game assets and behaviour"""
    def _init_(self):
        """initialise the game, and create game resources"""
        pygame.init()
        self.screen = pygame.display.set_mode((1200, 800))
        pygame.display.set_caption("Alien Invasion")
        #set the background colour.
        self.bg_color = (230, 230, 230)
    def run_game(self):
        """start the main loop for the game."""
        while True:
            #watch for keyboard and mouse events.
            for event in pygame.event.get():
                if event.type ==pygame.QUIT:
                    sys.exit()
        #redraw the screen during each pass through the loop.
                    self.screen.fill(self.bg_color)
#make the most recently drawn screen visible.
pygame.display.flip()
if __name__ == '__main__':
    #make a game instance, and run the game.
    ai = AlienInvasion()
    ai.run_game