NewbieGuide | Android quickly realizes the novice guide layer library | Learning library

    def _update_surfaces(self):
        """Updates rectangles in self.oldrects to reduce latency. If the list is empty, update the
        entire screen."""
        if self.oldrects:
            pygame.display.update(self.oldrects)
            self.oldrects = []
        else:
            pygame.display.flip()

    def _check_events(self):
        """Respond to events."""
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                sys.exit()
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_RIGHT:
                    # Move the ship to the right.
                    self.ship.rect.x += 1

    def _update_screen(self):
        """Update surface rects, update individual surfaces on the screen."""
        self.screen.fill(self.settings.bg_color)
        self.char.blit()

        self._add_old_rect(self.char) # Add surface to old list
        self._update_surfaces() # Update individual surfaces

    def run_game(self):
        """Start main game loop."""
        self.screen.fill(self.settings.bg_color)
        self._update_surfaces() # Update sceen
        while True:
            self._check_events()

            self._update_screen()