Chengbo Zhou

Really thanks for your answers!!! I have moved the modules to the dist-packages and given the read permission. Now the modules can be imported. But the other error shows up...

Got the solution from your hint. Thanks! The README of PI maybe should be updated. 

Hahaha, I have already struggled with it for two months. Currently I want to communicate with the switch via P4runtime API. That's why several problems raised up. But everything works...