auto save

snake.py

@@ -59,6 +59,7 @@ while True:
         num2 = random.randint(1,16)
         apple_x = 30*num1-30
         apple_y = 30*num2-30
+    else:
         position.pop(0)
     # 将背景图画上去
     screen.blit(background, (0, 0))