def needs_min_max_values(mode, buckets):
    """
    Returns True, if an encoding mode needs minimum and maximum column values, otherwise False
    """
    return not buckets and mode in ['one-hot',
                                    'one-hot-gaussian',
                                    'one-hot-gaussian-fluent',
                                    'unary',
                                    'unary-gaussian',
                                    'unary-gaussian-fluent']