I installed the relevant Python packages first e.g.
sudo apt-get install flake8 python3-flake8 python3-pep8 python-pep8-naming python3-setuptools pylint3
Then on the Atom menu use: Edit > Preferences 
then search for atom packages such as flake8, pep8, pep257 and pylint:
Then click the install button.
After restarting style advice is shown in the editor:
