save project

snake.py

@@ -63,10 +63,13 @@ while True:
         apple_y=n2*30-30
     else:    
         position.pop(0)
+    if x<0 or x>360 or y<0 or y>450:
+        exit()
     # 将背景图画上去
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去
     screen.blit(snake_head, position[-1])
+    
     # 将贪吃蛇的身体画上去
     for i in range(len(position)-1):
         screen.blit(body, position[i])