Python Error "ImportError: No module named pkg_resources"

I encountered the ImportError today while trying to use pip. Somehow the setup tools package had been deleted in my Python environment.

=============== File "/usr/bin/gunicorn", line 5, in <module> from pkg_resources import load_entry_point ImportError: No module named pkg_resources ===============

Fix to reset to python Environment curl https://bootstrap.pypa.io/ez_setup.py | python