save project

snake.py

@@ -62,7 +62,9 @@ while True:
         apple_y = 30*num2-30
         apple_y = 30*num2-30
     else:
     else:
         position.pop(0)
         position.pop(0)
-    # 将背景图画上去
+    if x > 630 or x < 0 or y > 450 or y < 0:
+        exit()
+    # 将背景图画上去 
     screen.blit(background, (0, 0))
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去
     # 将贪吃蛇的头画上去
     screen.blit(snake_head, position[-1])
     screen.blit(snake_head, position[-1])