def split_train_test(data_raw):
    """
    splits data into 3:7 split
    :param data_raw: raw data
    :return: return train and test data
    """
    data_train = data_raw[int(len(data_raw) / 10 * 3):]
    data_test = data_raw[:int(len(data_raw) / 10 * 3)]
    return data_train, data_test