👀 Views: 735 💬 Answers: 1 📅 Created: 2025-06-07

django oop inheritance Python

Can someone help me understand I'm prototyping a solution and I'm working on a project and hit a roadblock. Quick question that's been bugging me - After trying multiple solutions online, I still can't figure this out. I'm facing an issue with method overriding in Django models. I have a base model class that defines a method to return a custom string representation of the object. When I override this method in a subclass and try to use it in a QuerySet operation, I'm not seeing the expected behavior. Here's a simplified version of my code: ```python from django.db import models class BaseModel(models.Model): class Meta: abstract = True def custom_string(self): return 'BaseModel' class MyModel(BaseModel): name = models.CharField(max_length=100) def custom_string(self): return f'MyModel: {self.name}' # Using the QuerySet objects = MyModel.objects.all() for obj in objects: print(obj.custom_string()) ``` I expect this to print `MyModel: {name}` for each object in the database, but instead, it sometimes returns `BaseModel` for certain objects, especially when I filter or annotate the queryset. I have verified that all objects are instances of `MyModel`, but it seems like the `custom_string` method is not being overridden correctly in the context of the queryset. I've tried adding explicit calls to `MyModel.objects.get(pk=obj.pk)` inside the loop to see if that changed the result, but it didn't help. I'm using Django 4.1. I've also checked if there are any issues with database caching or how the queryset is executed, but I couldn't find anything that points to a solution. Does anyone have insights on how method resolution works in Django models, especially when it involves inherited methods in QuerySets? Could this be related to how Django handles model instances and their methods, or am I missing something in my setup? What's the best practice here? I'm working on a service that needs to handle this. I'd really appreciate any guidance on this. I'd really appreciate any guidance on this. The stack includes Python and several other technologies. Thanks for any help you can provide!