Django NestedObjects like in SqlAlchemy

Question

In the stackoverflow below is mention how to fetch all related objects in Django

Get all related Django model objects

To be short, the solution that best fits my needs would be something like code below..

from django.contrib.admin.utils import NestedObjects
collector = NestedObjects(using="default") #database name
collector.collect([objective]) #list of objects. single one won't do
print(collector.data)

Basically I'm trying to figure out how to do the same approach but using SqlAlchemy.

Thanks in advance!!