Django M2M

models.py

# -*- coding: utf-8 -*-
from django.db import models


class Person(models.Model):
    name = models.CharField(max_length=128)


class Group(models.Model):
    name = models.CharField(max_length=128)
    members = models.ManyToManyField(Person, through='Membership')


class Membership(models.Model):
    person = models.ForeignKey(Person, on_delete=models.CASCADE)
    group = models.ForeignKey("Group", on_delete=models.CASCADE)
    date_joined = models.DateField()
    invite_reason = models.CharField(max_length=64)