Django: Migrate all of a Users FK and OneToOne fields to another user

migrate_user.py

from typing import Any, List, Type, Union

from django.apps import apps
from django.db import transaction
from django.db.models import Model
from django.db.models.fields import Field
from django.db.models.fields.related import ForeignKey, ForeignObjectRel, OneToOneField

class MigrateUser:
    def __init__(self, _from_id: int, to_id: int) -> None:
        self._from_id = _from_id
        self.to_id = to_id
        self._from: User = User.objects.get(id=_from_id)
        self.to: User = User.objects.get(id=to_id)

    def run(self) -> None:
        with transaction.atomic():
            for model in self.get_models_to_migrate():
                model_fields = self.get_foreign_key_and_one_to_one_related_fields(model)
                self.update_model_based_on_fields(model, model_fields)

    def get_models_to_migrate(self) -> List[Type[Model]]:
        return apps.get_models()

    def is_user_related_field(self, field: Union[Field[Any, Any], ForeignObjectRel]) -> bool:
        """
        Check if the relationship is either a FK or 1-to-1 as they act the same
        """
        return field.__class__ in [ForeignKey, OneToOneField] and field.related_model == User

    def get_foreign_key_and_one_to_one_related_fields(self, model: Type[Model]) -> List[str]:
        return [field.name for field in model._meta.get_fields() if self.is_user_related_field(field)]

    def update_model_based_on_fields(self, model: Type[Model], model_fields: List[str]) -> None:
        for field_name in model_fields:
            # get all records based on the field for the old user
            filters = {field_name: self._from_id}
            results = model.objects.filter(**filters)

            # update all of the records we just got to the new user
            results.update(**{field_name: self.to_id})