YANG (RFC6020) is a data modelling language, it’s a way of defining how data is supposed to look like. The napalm-yang library provides a framework to use models defined with YANG in the context of network management. It provides mechanisms to transform native data/config into YANG and vice versa.
You can take a look to the following tutorial to see what this is about and how to get started.
napalm-yang you can use pip as with any other driver:
pip install -U napalm-yang