save project

snake.py

@@ -59,7 +59,7 @@ while True:
         apple_y=30*random.randint(0,15)
     else:
         position.pop(0)
-    
+    if x<0 or x>660 or y<0 or y>480
     # 将背景图画上去
     screen.blit(background, (0, 0))
     next