making script python3 proof

scripts/tracewin

 #!/usr/bin/env python
+from __future__ import print_function
 
 import argparse
 import os
@@ -72,13 +73,13 @@ for arg in ['dst_file1', 'dst_file2',
 
 if args.outpath:
     if not os.path.isdir(args.outpath):
-        print "WARNING: output directory does not exist, creating.."
+        print("WARNING: output directory does not exist, creating..")
         os.makedirs(args.outpath)
     cmd.append("path_cal='"+os.path.abspath(args.outpath)+"'")
 if args.seed:
     cmd.append("random_seed="+str(args.seed))
 
-print ' '.join(cmd)
+print(' '.join(cmd))
 if args.run:
     # TraceWin gives error when using subprocess.call (both for shell equals True and False)
     #subprocess.call(cmd)