删除部分无效外部引用

source/component/menubar.py

@@ -1,6 +1,5 @@
 import os
 import random
-from select import select
 import pygame as pg
 from .. import tool
 from .. import constants as c

source/state/level.py

@@ -1,6 +1,5 @@
 import os
 import json
-import sys
 import pygame as pg
 import random
 from .. import tool

source/tool.py

@@ -1,6 +1,5 @@
 import os
 import json
-import sys
 from abc import abstractmethod
 import pygame as pg
 from pygame.locals import *