pyEfi is a set of python tools in cli form used to gather data from Megasquirt ECU's via the serial interface, store and publish that data via a Redis unix socket, then display and process that data in different ways.
For a second i thought pyEfi was a tool for fetching and displaying megasquirt data on microcontrollers (ESP32 for example) but its for linux based operation systems like a laptop or raspberry correct?