docs: def file_or_resource(fname=None):
      '''get filename and check if in getcwd then get from
      the package resources folder
      '''
      if fname is not None:
          filename = os.path.expanduser(fname)
      
          resource_package = opentargets_validator.__name__
          resource_path = os.path.sep.join(('resources', filename))
  
          abs_filename = os.path.join(os.path.abspath(os.getcwd()), filename) \
                         if not os.path.isabs(filename) else filename
  
          return abs_filename if os.path.isfile(abs_filename) \
              else res.resource_filename(resource_package, resource_path)