How to set int column data to null with psycopg2

Question

I have this code and I'm trying to update a data row value to Null to test that it can be reselected on the front-end with Selenium Webdriver. It works fine when I run the sql manually against the data base but when I try to parameter substitute Null for an int column I get

Here is the meaningful part of the stack

cursor.execute(query, (REASONS_CREATED[reason_created], order_id))
DataError: invalid input syntax for integer: "Null"
LINE 4:     reason_created_id = E'Null'

Here is my code:

def update_reason_created_on_order(order_id, reason_created, environment='test'):
    '''
    Updates an order's reason created.
    '''
    sql_directory = find_path_to_sql_directory()
    with open(os.path.join(sql_directory, 'update_reason_created_on_order')) as sql:
        cursor = setup_database_cursor(environment)
        query = sql.read()
        try:
            cursor.execute(query, (REASONS_CREATED[reason_created], order_id))
        except:
            raise

Here is my Null entry for my REASONS_CREATED dictionary lookup

REASONS_CREATED = {'NULL': 'Null'}

Here is my sql in an external file

UPDATE
    order
SET
    reason_created_id = %s
WHERE
    order_id = %s;
COMMIT;

I understand that psycopg2 does automatic type conversion and recognizes this reason_created_id is type int. Does anyone know how to set it to null? Also, the column is nullable.

Answer 1

Just use None, the Python equivalent of SQL NULL.

Note: not the string "None" but the Python singleton None (without quotes).