I'm using Haystack Django for search engine.
conds['name'] = Exact(name)
conds['category'] = Exact(category)
conds['city_id'] = Exact(city_id)
conds['sub_category'] = list(city_id)
OK, the question seem to not clearly, I meant I want to add the key sub_category into the dictionary conds that values are list. So i found this way could answer the question above:
conds['sub_categary__in'] = sub_category_list