auto save

snake.py

@@ -59,7 +59,8 @@ while True:
         num2 = random.randint(1,16)
         apple_x = 30*num1-30
         apple_y = 30*num2-30
-    position.pop(0)
+    else:
+        position.pop(0)
     # 将背景图画上去
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去