Start updating fnlo-compare-ab.py for py3

tools/plotting/fnlo-compare-ab.py

-#!/usr/bin/env python2
+#!/usr/bin/env python3
 #-*- coding:utf-8 -*-
 #
 # Make comparison plots between two predictions
@@ -15,7 +15,7 @@ import glob
 import os
 import re
 import sys
-from StringIO import StringIO
+from io import StringIO
 import matplotlib.lines as mpllines
 import matplotlib.gridspec as gridspec
 import matplotlib.patches as mplpatches
@@ -30,9 +30,9 @@ import numpy as np
 #from fnlo_parsers import FNLOCppReadOutputParser
 #from fnlo_parsers import FNLOYodaOutputParser
 # fastNLO
-#import fastnlo
-#from fastnlo import fastNLOLHAPDF
-#from fastnlo import SetGlobalVerbosity
+import fastnlo
+from fastnlo import fastNLOLHAPDF
+from fastnlo import SetGlobalVerbosity
 
 # Redefine ScalarFormatter
 
@@ -105,16 +105,16 @@ def main():
     exit(0)
 
     # Extract no. of columns from files
-    print 'Reading no. of columns from 1st file ', afile
+    print ('Reading no. of columns from 1st file ', afile)
     cols = np.loadtxt(afile, comments=['#', ' #', 'C', 'L'])
     nacol = cols.shape[1]
-    print 'Found ', nacol, ' columns'
-    print 'Reading no. of columns from 2nd file ', bfile
+    print ('Found ', nacol, ' columns')
+    print ('Reading no. of columns from 2nd file ', bfile)
     cols = np.loadtxt(bfile, comments=['#', ' #', 'C', 'L'])
     nbcol = cols.shape[1]
-    print 'Found ', nbcol, ' columns'
+    print ('Found ', nbcol, ' columns')
     if nacol != nbcol:
-        print 'Different no. of columns found, aborted!'
+        print ('Different no. of columns found, aborted!')
         exit(1)
         ncol = nacol
 
@@ -125,7 +125,7 @@ def main():
         iobsb, bwb, id0b, xlb, xub, xaveb, xsb_lo, xsb_nlo, kb_nlo = np.loadtxt(bfile, comments=['#', ' #', 'C', 'L'], dtype=[(
             'f0', int), ('f1', float), ('f2', int), ('f3', float), ('f4', float), ('f5', float), ('f6', float), ('f7', float), ('f8', float)], unpack=True)
     else:
-        print 'ncol different from 9 not yet implemented. Aborted!'
+        print ('ncol different from 9 not yet implemented. Aborted!')
         exit(2)
 
     exit(0)
@@ -136,10 +136,10 @@ nvala = iobsa.size
 nvalb = iobsb.size
 nobsa = max(iobsa)
 nobsb = max(iobsb)
-print 'Found ', nvala, ' result lines for ', nobsa, ' observable bins in file ', afile
-print 'Found ', nvalb, ' result lines for ', nobsb, ' observable bins in file ', bfile
+print ('Found ', nvala, ' result lines for ', nobsa, ' observable bins in file ', afile)
+print ('Found ', nvalb, ' result lines for ', nobsb, ' observable bins in file ', bfile)
 if nvala != nvalb or nobsa != nobsb:
-    print 'nval or nobs different between the two files to compare, aborted!'
+    print ('nval or nobs different between the two files to compare, aborted!')
     exit(3)
 nobs = nobsa
 nval = nvala