The data structure you want to use is a dictionary - known as hashmap or hash or map in other languages. Lets say you have a few objects of type town that you want to access using their zip, then things could look like this:
------------ class Town(object): def __init__(self, zip, cool_clubs): self.zip = zip self.colo_clubs = cool_clubs towns = [Berlin(10439, ["Marietta", "ICON", "Bastart"]), Cologne(50000, ["Subway", "Stadtgarten", "Gebäude 9"])] index = {} for town in towns: index[town.zip] = town ---------------- Hope that makes it clear to you - look into the tutorial for a chapter about python data structures. -- Regards, Diez B. Roggisch -- http://mail.python.org/mailman/listinfo/python-list