def get_filenames(ruleset_db, rule):
    """returns a list of all filenames for a rule in a ruleset"""
    from src.praxxis.sqlite import connection
    conn = connection.create_connection(ruleset_db)
    cur = conn.cursor()
    list_filenames = 'SELECT Filename FROM "Filenames" WHERE Rule = ?'
    cur.execute(list_filenames, (rule,))
    conn.commit()
    filenames = cur.fetchall()
    conn.close()
    return filenames
