def _index_ordering ( redshift_list ) : redshift_list = np . array ( redshift_list ) sort_index = np . argsort ( redshift_list ) return sort_index
indexes of sorted list python
def _index_ordering(redshift_list):
        """

        :param redshift_list: list of redshifts
        :return: indexes in acending order to be evaluated (from z=0 to z=z_source)
        """
        redshift_list = np.array(redshift_list)
        sort_index = np.argsort(redshift_list)
        return sort_index