Restrict the cosmology to the redshifting module. It does not make much sense in other modules.

pcigale/creation_modules/fritz2006.py

@@ -14,7 +14,6 @@ from collections import OrderedDict
 import numpy as np
 from pcigale.data import Database
 from . import CreationModule
-from pcigale.sed.cosmology import cosmology
 
 
 class Fritz2006(CreationModule):

pcigale/creation_modules/redshifting.py

@@ -23,7 +23,7 @@ from scipy.constants import parsec
 from scipy.misc import factorial
 
 from ..creation_modules import CreationModule
-from pcigale.sed.cosmology import cosmology
+from astropy.cosmology import WMAP7 as cosmology
 
 
 def igm_transmission(wavelength, redshift):

pcigale/sed/cosmology.py

-# -*- coding: utf-8 -*-
-# Copyright (C) 2013 Centre de données Astrophysiques de Marseille
-# Licensed under the CeCILL-v2 licence - see Licence_CeCILL_V2-en.txt
-# Author: Yannick Roehlly
-"""Cosmology configuration
-
-We use astropy.cosmology module. For now, we import the desired cosmology here
-so that it can be changed easily for people needing a specific cosmology.
-
-"""
-
-from astropy.cosmology import WMAP7 as cosmology

pcigale_plots/__init__.py

@@ -18,7 +18,6 @@ import numpy as np
 import os
 import pkg_resources
 from scipy.constants import c, parsec
-from pcigale.sed.cosmology import cosmology
 from pcigale.data import Database
 from pcigale.utils import read_table
 from pcigale.session.configuration import Configuration