How Could I Optimise This Simple Python Pygame Code

I've been set a challenge to make a game using pygame ( I am making snake so it should be easy... but I've never used pygame) so using a more efficient language isn't an option.So

Solution 1:

To improve the game's performance, draw the grid on a pygame.Surface object with the size of the screen, before the application loop:

defdrawGrid(surf):
    surf.fill(grey)
    blockSize = 10for x inrange(display_width):
        for y inrange(display_height):
            rect = pygame.Rect(x*blockSize, y*blockSize,blockSize, blockSize)
            pygame.draw.rect(surf, darkgrey, rect, 1)

grid_surf = pygame.Surface(display.get_size())
drawGrid(grid_surf)

blit the surface once per frame on the display instead of drawing the grid once per frame, in the application loop:

defSnakeGameLoop():
    # [...]whilenot game_over:
        # [...]

        display.blit(grid_surf, (0, 0))
        
        pygame.draw.rect(display,puregreen,[X,Y,10,10])

        pygame.display.update()