No module named pip.req

This is happening lately because of a change in pip 10.

The fix is pretty easy. You probably have something like:

from pip.req import parse_requirements

Change that to something like:

try: # for pip >= 10
    from pip._internal.req import parse_requirements
except ImportError: # for pip <= 9.0.3
    from pip.req import parse_requirements

That should do it.