I’m facing an issue while trying to access deeply nested attributes within the validate method of a Django Rest Framework serializer. Here’s a simplified version of my serializer:

from rest_framework import serializers
from myapp.models import User

class YourSerializer(serializers.ModelSerializer):

    def validate(self, attrs):
        if hasattr(self.parent.instance, 'vehicle'):
            if hasattr(self.parent.instance.vehicle, 'engine'):
                if hasattr(self.parent.instance.vehicle.engine, 'fuel'):
                    fuel_type = self.parent.instance.vehicle.engine.fuel.diesel
                    if fuel_type:
                        pass
                    else:
                        raise serializers.ValidationError("Fuel type is not available.")
                else:
                    raise serializers.ValidationError("Fuel attribute is not available.")
            else:
                raise serializers.ValidationError("Engine attribute is not available.")
        else:
            raise serializers.ValidationError("Vehicle attribute is not available.")
        
        return attrs

In the validate method, I’m attempting to access deeply nested attributes (vehicle.engine.fuel.diesel) of the parent instance.
The thing is Model engine is created after user does ABC operations, and same applies for fuel, and diesel. When a load of people work on
codebase its tough to identify if a these Models are created or not, normally getattr() and hasattr() are used, but clubbing these a lot makes
code look messy.

Tried static loots like mypy and pylint, they help to a certain extent but sometimes, TypeError, NoneType issues popup.
Not sure how to fix these.

Thank you for your help!