save project

snake.py

@@ -62,7 +62,8 @@ while True:
         apple_y=gz_y*30-30
     else:
         position.pop(0)
-
+    if x>660 or y>480 or x<0 or y<0:
+        exit()
     # 将背景图画上去
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去