auto save

snake.py

 import pygame
 from pygame import locals
+import random
 
 # 初始化pygame，为使用硬件做准备
 pygame.init()
@@ -52,6 +53,7 @@ while True:
     else:
         y += 30
     position.append((x, y))
+    
     position.pop(0)
     # 将背景图画上去
     screen.blit(background, (0, 0))