InheritanceCastModel

This abstract base class can be inherited by the root (parent) model in a model-inheritance tree. It allows each model in the tree to "know" what type it is (via an automatically-set foreign key to ContentType), allowing for automatic casting of a parent instance to its proper leaf (child) type.

For instance, if you have a Place model with subclasses Restaurant and Bar, you may want to query all Places:

nearby_places = Place.objects.filter(location='here')

But when you iterate over nearby_places, you'll get only Place instances back, even for objects that are "really" Restaurant or Bar. If you have Place inherit from InheritanceCastModel, you can just call the cast() method on each Place and it will return an instance of the proper subtype, Restaurant or Bar:

from model_utils.models import InheritanceCastModel

class Place(InheritanceCastModel):
    ...

class Restaurant(Place):
    ...

nearby_places = Place.objects.filter(location='here')
for place in nearby_places:
    restaurant_or_bar = place.cast()
    ...

TimeStampedModel

This abstract base class just provides self-updating created and modified fields on any model that inherits it.