We want to have multiple types of Articles so we need to make our existing Article model abstract.

from django.db import models


class Article(models.Model):
    headline = models.CharField(max_length=255)
    publish_date = models.DateTimeField()
    content = models.TextField()
    writer = models.ForeignKey('Writer')

    def __str__(self):
        return self.headline


class Writer(models.Model):
    name = models.CharField(max_length=255)
    email = models.EmailField()
    bio = models.TextField()

    def __str__(self):
        return self.name

    def mailto(self):
        return '{} <{}>'.format(self.name, self.email)

class Article(models.Model):
    total_article = models.AutoField(primary_key=True)