problem with saved_model.evaluate on Python 3.7

[ryanmark1867]

saved_model = load_model(save_model_path)
_, train_acc = saved_model.evaluate(X_train_list, dtrain.target, verbose=0)
_, test_acc = saved_model.evaluate(X_test, test.target, verbose=0)
print('Train: %.3f, Test: %.3f' % (train_acc, test_acc))

get the following error:

ValueError Traceback (most recent call last)
in ()
1 saved_model = load_model(save_model_path)
----> 2 _, train_acc = saved_model.evaluate(X_train_list, dtrain.target, verbose=0)
3 _, test_acc = saved_model.evaluate(X_test, test.target, verbose=0)
4 print('Train: %.3f, Test: %.3f' % (train_acc, test_acc))

ValueError: too many values to unpack (expected 2)