Mastering Django: Core

Model methods

Define custom methods on a model to add custom row-level functionality to your objects. Whereas managers are intended to do table-wide things, model methods should act on a particular model instance. This is a valuable technique for keeping business logic in one place-the model.

An example is the easiest way to explain this. Here's a model with a few custom methods:

from django.db import models class Person(models.Model): first_name = models.CharField(max_length=50) last_name = models.CharField(max_length=50) birth_date = models.DateField() def baby_boomer_status(self): # Returns the person's baby-boomer status. import datetime if self.birth_date < datetime.date(1945, 8, 1): return "Pre-boomer" elif self.birth_date < datetime.date(1965, ...