code: def _get_data_file_path(data_file):
      
  
      try:
  
          file_path = pkg_resources.resource_filename("astromodels", 'data/%s' % data_file)
  
      except KeyError:
  
          raise IOError("Could not read or find data file %s. Try reinstalling astromodels. If this does not fix your "
                        "problem, open an issue on github." % (data_file))
  
      else:
  
          return os.path.abspath(file_path)
docs: Returns the absolute path to the required data files.
  
      :param data_file: relative path to the data file, relative to the astromodels/data path.
      So to get the path to data/dark_matter/gammamc_dif.dat you need to use data_file="dark_matter/gammamc_dif.dat"
      :return: absolute path of the data file