from rest_framework import serializers class UsernameSerializer(serializers.Serializer): id = serializers.IntegerField() username = serializers.CharField() real_name = serializers.SerializerMethodField() def __init__(self, *args, **kwargs): self.is_admin_role = kwargs.pop("is_admin_role", False) super().__init__(*args, **kwargs) def get_real_name(self, obj): return obj.userprofile.real_name if self.is_admin_role else None