Pull constant python_tag out of loop.
Pull constant python_tag out of loop.

pfmoore/pip,pypa/pip,sbidoul/pip,pypa/pip,rouge8/pip,pradyunsg/pip,xavfernandez/pip,pfmoore/pip,xavfernandez/pip,rouge8/pip,sbidoul/pip,xavfernandez/pip,rouge8/pip,pradyunsg/pip