This was for `benwilber` in #django in reference to this ML thread: https://groups.google.com/forum/#!topic/django-users/Zz9rKT7GVM0

this_should_work.py

def populate_initial_data(apps, schema_editor):
    
    
    User = apps.get_model(settings.AUTH_USER_MODEL)
    Group = apps.get_model('auth', 'Group')

    user = User(username="test", email="[email protected]")
    # you need to know how to set the password ... ugh
    # I'm assuming User().set_password doesn't exist?
    from django.contrib.auth.hashers import make_password
    user.password = make_password('test')
    user.save()

    # this should, I hope, work, because neither is a real model
    group = Group.objects.create(name="Test Group")
    user.groups.add(group)
    
    # Or you could probably do ... I can't recall if you need to 
    # .save() afterwards
    user.groups = [group]

this_should_work2.py

def populate_initial_data(apps, schema_editor):
    # this is bad because now your historic data migration is 
    # tied to your current User model ...
    from django.contrib.auth import get_user_model
    User = get_user_model()
    
    # realistically, if you've imported a conrete User instance, you may
    # as well import the concrete Group instance, which would definitely avoid
    # the TypeError.
    Group = apps.get_model('auth', 'Group')

    # this will work because you've imported the real model, but should be avoided
    user = User.objects.create_user("test", email="[email protected]", password="test")
    
    group = Group.objects.create(name="Test Group")
    # this won't work because Group != auth.Group, technically.
    # user.groups.add(group)
    
    # This might work.
    M2M = user.groups.through
    M2M.objects.create(user_id=user.pk, group_id=group.pk)