Question

How can I associate lists apps Listing model with an user. User has_many lists.

What shall I include in my List model for being able to use models.ForeignKey(User)

Answer 1

Here you go (Although you should just look at the Django DOcs the next Time):

from django.db import models
from django.contrib.auth.models import User

class Listing(models.Model):
    user = models.ForeignKey(User)

Hope this helps