def interpret_bit_order(bit_order):
    """interpret bit_order for use in :func:`numpy.unpackbits` so that it also '>' and '<' can be used"""
    if bit_order == 'little' or bit_order == 'big':
        return bit_order
    elif bit_order == '<':
        return 'little'
    elif bit_order == '>':
        return 'big'
    else:
        raise ValueError("argument bit_order can receive '<', '>', 'little' or 'big' but got " + bit_order)