DjangoRestFramework—将“required = false”添加到模型序列化器字段的正确方法?

This is my serializer:

这是我的序列化器:

class PostSerializer(serializers.ModelSerializer):

    class Meta:
        model = Post
        fields = ('user', 'post', 'reblog',)

    def create(self, validated_data):
        post = Post(
                user =  validated_data['user'],
                post = validated_data['post'],
        )

        post.save() 

        # manually create a list of "reblog" users
        post.reblog.add(validated_data['user'])

        return post
class Post