Virtualenvs in python are cheap but from time to time you will install something with pip on your system and when time comes removing all this crap could be difficult. I found this bash snippet1 that will uninstall package with all dependencies:

Recursive pip uninstall
for dep in $(pip show python-neutronclient | grep Requires | sed 's/Requires: //g; s/,//g') ; do
  pip uninstall -y $dep ;
pip uninstall -y python-neutronclient

Depending how you installed it, you might need to use sudo.