Django 4.2: implementing Serializing Nested Relationships in DRF with Custom Fields
I'm collaborating on a project where I'm writing unit tests and I'm currently working on a Django 4.2 project using Django Rest Framework (DRF) and working with scenarios when trying to serialize a nested relationship that includes custom fields... I have a `Book` model that has a foreign key to an `Author` model. Each `Author` has a custom field that I want to include in the serialized output. Here's a simplified structure of my models: ```python class Author(models.Model): name = models.CharField(max_length=100) bio = models.TextField() award_count = models.IntegerField(default=0) class Book(models.Model): title = models.CharField(max_length=200) published_date = models.DateField() author = models.ForeignKey(Author, on_delete=models.CASCADE) ``` In my serializer, I'm trying to include the `award_count` from the `Author`, but I keep getting an behavior: `KeyError: 'award_count'`. Here’s how I’ve implemented my serializers: ```python from rest_framework import serializers class AuthorSerializer(serializers.ModelSerializer): class Meta: model = Author fields = ['name', 'bio', 'award_count'] class BookSerializer(serializers.ModelSerializer): author = AuthorSerializer() # Nested serialization class Meta: model = Book fields = ['title', 'published_date', 'author'] ``` I expect the serialized output for a book to include the author's `award_count`, but when I access it, it fails with the mentioned KeyError. I’ve tried debugging by checking the `Author` instance being passed to the `AuthorSerializer`, and it seems to properly contain `award_count`. I also confirmed that the field is present in the database and correctly populated. Additionally, I tried changing the serializer to explicitly fetch the `award_count` in the `BookSerializer` with a custom method field, but that didn’t yield the expected results either. Is there a specific approach I should follow to ensure that the nested relationships serialize correctly in DRF? Any insights on how to resolve this would be greatly appreciated! I'm working in a Windows 11 environment. What's the best practice here? This is my first time working with Python stable.