简单的命令行示范：

print("欢迎进入修仙系统")
while True: #持续循环
    action = input("请输入要执行的操作：")
    if action in ["1","2","3","esc"]:
        if action == "1":
            print("练气")
        elif action == "2":
            print("筑基")
        elif action == "3":
            print("结丹")
        elif action == "esc":
            print("您已退出")
            break