def redis_hash_to_dict(redis_hash):
    """convert redis hash to python dict.

    Args:
        redis_hash: redis hash object, a dict with all keys and values in byte.

    Return:
        a python dict with all keys and values in string.

    """
    return {k.decode("utf-8"): v.decode("utf-8") if v else ""
            for k, v in redis_hash.items()}