detail.py

from posts.models import Post
from rest_framework import serializers


class PostDetailSerializer(serializers.HyperlinkedModelSerializer):

	username = serializers.CharField(source="user.username")

	class Meta:
		model = Post
		fields = (
			'title',
			'username',
			'content',
			'created_at',
			'updated_at',
			'is_public',
			'comment',
		)