drf-serializer-inheritance.py

# parent_serializer.py
class MetaObj():
  pass

class ParentSerializer(serializers.ModelSerializer):
    def __init__(self, *args, **kwargs):
        meta_obj = MetaObj()
        meta_obj.model = ParentModel
        meta_obj.fields = ["field_1", "field_2"]
        meta_obj.read_only_fields = ["field 3", "field_4"]
        self.Meta = meta_obj  
        super().__init__(*args, **kwargs)
        
        
        
# child_serializer.py
class ChildSerializer(ParentSerializer):
    new_field = serializers.CharField(default="this a new added field coming form child serializer.")
    # Approach 1: Appending the "new_field" to the existing fields that ParentSerializer has
    class Meta:
        parent_serializer = ParentSerializer()
        existing_fields = parent_serializer.Meta.fields
        fields = list(parent_serializer.Meta.fields) + ["new_field"]

    # Approach 2: Appending the "reports" field in the constructor and creating meta within constructor.
    def __init__(self, *args, **kwargs):
        parent_serializer = ParentSerializer(*args, **kwargs)
        self.Meta = parent_serializer.Meta
        self.Meta.fields = list(parent_serializer.Meta.fields)
        self.Meta.fields.append("new_field")
        super().__init__(*args, **kwargs)