这个聊天室项目全部由Python完成。
目前还只是1.0版本，只能在终端上运行。
因为使用的是Python在Windows、Linux和MacOS都通用的库，所以这个代码可以在这三个系统上任意运行。
将来还会使用PyQT完成有GUI的终极版本，这也是为什么会有不明所以的utils.py文件。
This chat app is implemented by Python totally.
At present it's version 1.0, only run in terminal
As it uses Python library compatible for Windows, Linux and MacOS, so this chat app can run on these 3 systems as you like.
In further future I'll use PyQT to add GUI for the final version, and this is the reason why here comes an inexplicable file named utils.py