How to use Python type hints with Django QuerySet?

Question

Is it possible to specify type of records in Django QuerySet with Python type hints? Something like QuerySet[SomeModel]?

For example, we have model:

Answer 1

IMHO, the proper way to do it is to define a type that inherits QuerySet and specify a generic return type for the iterator.

    from django.db.models import QuerySet
    from typing import Iterator, TypeVar, Generic, Optional

    T = TypeVar("T")


    class QuerySetType(Generic[T], QuerySet):  # QuerySet + Iterator

        def __iter__(self) -> Iterator[T]:
            pass

        def first(self) -> Optional[T]:
            pass

        # ... add more refinements

Then you can use it like this:

users: QuerySetType[User] = User.objects.all()
for user in users:
   print(user.email)  # typing OK!
user = users.first()  # typing OK!