I was calling lookup in my query with two input fields and three output fields. My query looks like ...|lookup names_lookup person_id,person_name OUTPUT person_first,person_last,person_middle my config in transforms.conf looks like [names_lookup] external_cmd = names_lookup_example.py person_id person_name person_first person_last person_middle external_type = python fields_list = person_id, person_name, person_first, person_last, person_middle And my script is trying to find fisrt and last names from another csv file using the person_id. If it finds a row in csv for that id return that data otherwise split the input field(person_name) and put them in the output fields. return it. So everything works except when person_name input is null or empty string the output fields were empty even though i have row in my csv file for that id. should all input values be not null for lookup to work? I can't modify input fields in the script.can we do that ? ... View more