Very basic, it will grab one screen shot by monitor or a screen shot of all monitors and save it to a PNG file, Python 2.6/3.5 compatible & PEP8 compliant. It could be easily embedded into games and other softwares which require fast and plateforme optimized methods to grab screenshots.
MSS stands for Multiple ScreenShots.
It's under MIT license and there is a beautiful documentation :).
You can install it with pip:
pip install --upgrade mss