I tried to perform training on my data and on toy example too. Command prompt doesnt show anything but the message about restarting.
segm_features = np.array([[1,0], [1,1], [0,1]])
labels = np.array([1,0,0])
cv_model = cv.ml.DTrees_create()
dtype = np.int32
train_data = cv.ml.TrainData_create(segm_features.astype(np.float32), cv.ml.ROW_SAMPLE, labels.astype(dtype))
cv_model.train(train_data)