diff --git a/processing/post/addCauchy.py b/processing/post/addCauchy.py
index 2f69cb043..2d366b198 100755
--- a/processing/post/addCauchy.py
+++ b/processing/post/addCauchy.py
@@ -68,7 +68,7 @@ for name in filenames:
 # ------------------------------------------ assemble header --------------------------------------
 
   table.info_append(scriptID + '\t' + ' '.join(sys.argv[1:]))
-  table.labels_append(['%i_Cauchy'%(i+1) for i in xrange(9)])                                       # extend ASCII header with new labels
+  table.labels_append(['{}_Cauchy'.format(i+1) for i in xrange(9)])                                 # extend ASCII header with new labels
   table.head_write()
 
 # ------------------------------------------ process data ------------------------------------------