Index: lib/fuzzer/scripts/merge_data_flow.py
===================================================================
--- lib/fuzzer/scripts/merge_data_flow.py
+++ lib/fuzzer/scripts/merge_data_flow.py
@@ -18,7 +18,7 @@
   res = array('b')
   for i in range(0, len(a)):
     res.append(ord('1' if a[i] == '1' or b[i] == '1' else '0'))
-  return res.tostring()
+  return res.tostring().decode('utf-8')
 
 def main(argv):
   D = {}
@@ -29,7 +29,11 @@
     else:
       D[F] = BV;
   for F in D.keys():
-    print("%s %s" % (F, str(D[F])))
+    if isinstance(D[F], str):
+      value = D[F]
+    else:
+      value = D[F].decode('utf-8')
+    print("%s %s" % (F, value))
 
 if __name__ == '__main__':
   main(sys.argv)