[Django] Simple task class and functions for adding/removing three types of tasks (tasks are for notifying the administrator that there is something to be done, and should be tied to an event and optionally an event registration object).

models.py

class Task(models.Model):

    REGISTRATION = 0
    ATTENDANCE = 1
    CLE = 2

    TASK_TYPES = (
        (REGISTRATION, 'Registration Request'),
        (ATTENDANCE, 'Attendance Request'),
        (CLE, 'CLE Request'),
    )

    task_type = models.PositiveSmallIntegerField(max_length=1, choices=TASK_TYPES, default=0)

    event = models.ForeignKey(Event)
    registration = models.ForeignKey(EventRegistration, blank=True, null=True)

    def __unicode__(self):
        return "{0} - {1}".format(self.event.title, self.TASK_TYPES[self.task_type][1])


# For registering actions that should trigger a task for the Firm Admin
def add_task(task_type, event, registration):
    try:
        Event.objects.get(pk=event.pk)
    except Event.DoesNotExist:
        return False

    if task_type == Task.REGISTRATION or task_type == Task.ATTENDANCE or task_type == Task.CLE:
        try:
            Task.objects.get(Q(task_type=task_type) & Q(registration=registration) & Q(event=event))
        except Task.DoesNotExist:
            Task(task_type=task_type, event=event, registration=registration).save()
            return True
    else:
        return False


# For clearing out tasks that have been completed
def remove_task(task_type, event, registration):
    try:
        Event.objects.get(pk=event.pk)
    except Event.DoesNotExist:
        return False

    if task_type == Task.REGISTRATION or task_type == Task.ATTENDANCE or task_type == Task.CLE:
        try:
            task = Task.objects.get(Q(task_type=task_type) & Q(registration=registration) & Q(event=event))
            task.delete()
            return True
        except Task.DoesNotExist:
            return False
    else:
        return False