diff --git a/nifty_core.py b/nifty_core.py
index e6354208678f288fee921bbdd66953c0e316e54c..a3f5d0c32874fa713ff5673d256a6d3490d15bba 100644
--- a/nifty_core.py
+++ b/nifty_core.py
@@ -111,20 +111,23 @@
         2013; `arXiv:1301.4499 <http://www.arxiv.org/abs/1301.4499>`_
 
 """
+## standard libraries
 from __future__ import division
 import os
 #import sys
 from sys import stdout as so
 import numpy as np
+import pylab as pl
+from matplotlib.colors import LogNorm as ln
+from matplotlib.ticker import LogFormatter as lf
+from multiprocessing import Pool as mp
+## third party libraries
 import gfft as gf
 import healpy as hp
 import libsharp_wrapper_gl as gl
+## internal libraries
 import smoothing as gs
 import powerspectrum as gp
-import pylab as pl
-from matplotlib.colors import LogNorm as ln
-from matplotlib.ticker import LogFormatter as lf
-from multiprocessing import Pool as mp
 
 
 pi = 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679
diff --git a/nifty_power.py b/nifty_power.py
index b9b6139b79a8761d94b37c957991237986c2e3b8..9244c09839a5d62423d0ab39ae7dc664ddaad662 100644
--- a/nifty_power.py
+++ b/nifty_power.py
@@ -40,10 +40,9 @@
     manipulation.
 
 """
-
 from __future__ import division
-from nifty_core import *
 #import numpy as np
+from nifty_core import *
 import smoothing as gs