Save Python dict to Redis hash

dict_to_redis.py

def dict_to_redis_hset(r, hkey, dict_to_store):
    """
    Saves `dict_to_store` dict into Redis hash, where `hkey` is key of hash.

    >>> import redis
    >>> r = redis.StrictRedis(host='localhost')
    >>> d = {'a':1, 'b':7, 'foo':'bar'}
    >>> dict_to_redis_hset(r, 'test', d)
    True
    >>> r.hgetall('test')
    {'a':1, 'b':7, 'foo':'bar'}
    """
    return all([r.hset(hkey, k, v) for k, v in dict_to_store.items()])

Does anyone know how to store a dict value? I get this error when I try to map a key to a dict value

DataError: Invalid input of type: 'dict'. Convert to a bytes, string, int or float first.