diff --git a/demo/multi_classification/train.py b/demo/multi_classification/train.py
index d4cf2a0d4..38d818890 100755
--- a/demo/multi_classification/train.py
+++ b/demo/multi_classification/train.py
@@ -37,6 +37,6 @@ bst = xgb.train(param, xg_train, num_round, watchlist );
 # get prediction
 pred = bst.predict( xg_test );
 
-print 'error=%f' % sum(int(pred[i]) != test_Y[i] for i in len(test_Y)) / float(len(test_Y)) 
+print 'predicting, classification error=%f' % (sum( int(pred[i]) != test_Y[i] for i in xrange(len(test_Y))) / float(len(test_Y)) )