Django Team Sport class

Question

So this isn't EXACTLY my code but it is close enough to show what I have. Also the naming is only for this site so if its not really clear forgive me. Its much clearer in the actual code.

class Member(models.Model):
    team = models.IntegerField(default=0)
    match = models.ForeignKey(Match, null=True, blank=True)

    def engage(self, match_instance, team_number):
        self.match = match_instance
        self.team = team_number
        self.save()

class NPCGeneric(models.Model):
    speed = models.IntegerField(default=1)
    difficulty = models.IntegerField(default=0)

class NPCInstance(Member):
    generic = models.ForiegnKey(NPCGeneric);
    status = models.CharField(max_length=50)

    def engage(self, match_instance, team_number):
        new_instance = NPCInstance(generic=self)
        new_instance.save()       
        return new_instance.engage(match_instance, team_number)

class Player(Member):
    name = models.CharField(max_length=100)


class Match(models.Model):
    event_members = []

    def __init__(self, *args, **kwargs):        
        retval = super(Match, self).__init__(*args, **kwargs)
        if(args[0] and hasattr(args[0], '__iter__')):
            teams = args[0]
            args = args[1:]
            self.__init_new__(teams)
        elif(self.id):
            self.__init_existing__()
        return retval

    def __init_new__(self, teams):
        new_teams = []
        for team in teams:
            new_team = []
            new_teams.append(new_team)
            team_number = new_teams.index(new_team)
            for event_member in team:
                team_member = event_member .engage(self, team_number)
                team_member .save()
                new_team.append(team_member)
        self.event_members = new_teams

    def __init_existing__(self):
        new_teams = []
        def add_list(list, member, team):
            while(list.__len__() < (team + 1)):
                list.append([])
            list[team].append(member)

        for event_member in self.member_set.all():
            try:
                member = event_member.npcinstance
            except:
                member = event_member.player
            add_list(new_teams, member, member.team)
        self.event_members= new_teams

So this is where I start thinking that there has to be a better cleaner way. Unfortunately my brain just keeps getting stuck on what I already have.

I'd love to know if anyone can suggest a cleaner/Pythonic way for holding the Members in the Match class. specifically:

• The initialising just seems very odd and clumsy. I'm afraid I will introduce errors this way.
• a better way of representing teams other than a list of lists event_members

Answer 1

Sorry, it just seems to me that issues lie outside of the piece of code that you're suggesting to review. The code itself is more or less fine, but some assumptions behind it seem not right.

I had thought about Team objects but I was hoping not to get too complex. i can't access the filtering in the templates either.

Well, you still have teams anyway, you're just passing them around "implicitly", by their numbers. IMO it actually makes it more complex, and is less "pythonic" (remember, explicit is better than implicit).

And, although I don't know the exact requirements, but maybe what you're trying to do in templates could be achieved another way?

Update in response to comment:

Also I want to point out that the code works. It just doesn't "mesh" in my head well.

The code may work, but it looks very… unconventional. And in Python conventions mean a lot. And in Django they mean even more: it's a framework, and, as any other framework, it has lots of design decisions already made for you. It allows you to focus on your data structures and your business logic, but it does that by taking from you some freedom.

So when you're starting to write such complex initialization methods, then probably something is going wrong. I'd say this, and "implicit" teams, are cases when you're beginning to "fight the framework". It's usually the losing battle. The conventional way is to just have a Team class. It will also make code more maintainable, which is very important. (What if the requirements change and you'll need to store more information about the team, not only its number?)

i am also trying to keep the number of different objects in the DB to a minimum but its not THAT important

Seems like premature optimization. I doubt that could be a performance bottleneck. Although it depends on your requirements.