Ubuntu 20.04 : pytest command gives this output -> E ImportError: No module named selenium, even after installing selenium

 Your selenium files will be inside /usr/local/lib/python3.8/dist-packages/

You have to copy and paste them in /usr/local/lib/python2.7/dist-packages/

and /usr/local/lib/python2.7/site-packages/

The main problem is there is python2 and python3 installed in your computer and python2 is actively used by your system now. And selenium is within python3 folder.