class Category(models.Model):
    name = models.CharField(max_length=80)


class Place(models.Model):
    name = models.CharField(max_length=50)
    address = models.CharField(max_length=80)
    category = models.ForeignKey('Category')


class PizzaRestaurant(Place):
    serves_hot_dogs = models.BooleanField(default=False)
    serves_pizza = models.BooleanField(default=False)


class PastaRestaurant(Place):
    extra = models.CharField(max_length=80)

a = Category()
a.name = "pasta"

b = Category()
b.name = "pizza"

a.save()
b.save()

x = PastaRestaurant()
x.address = "Pasta Address"
x.name = "Pastamonia"
x.extra = "some extra"
x.category = a

y = PizzaRestaurant()
y.address = "Pizza Address"
y.name = "Dominos"
y.serves_hot_dogs = 1
y.serves_pizza = 0
y.category = b

x.save()
y.save()

p = Place.objects.get(id=1)

class Place(PolymorphicModel):
    ...

class PizzaRestaurant(Place):
    ...

class PastaRestaurant(Place:
    ...


>>> some_place = Place.objects.create(name="Walmart")
>>> some_pizza_place = PizzaRestaurant.objects.create(name="Slice King", address="101 Main St., Bismarck, ND", category = Category.objects.first(),serves_pizza=True)
>>> some_pizza_place.instance_of(PizzaPlace)
True
>>> PizzaRestaurant.objects.all()
queryset<['Slice King',]>
>>> Place.objects.all()
queryset<['Walmart', 'Slice King',]>