Django JSON :用户类型的对象不是TypeError可序列化的

import json

class User:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def __json__(self):
        return {
            'name': self.name,
            'age': self.age
        }

user = User('John', 25)

# 序列化为JSON字符串
json_str = json.dumps(user, default=lambda obj: obj.__json__())
print(json_str)

# 反序列化为Python对象
user_obj = json.loads(json_str)
print(user_obj['name'])
print(user_obj['age'])

from rest_framework import serializers

class UserSerializer(serializers.Serializer):
    name = serializers.CharField()
    age = serializers.IntegerField()

user = User(name='John', age=25)

# 序列化为JSON字符串
serializer = UserSerializer(user)
json_str = serializer.data
print(json_str)

# 反序列化为Python对象
user_obj = UserSerializer(data=json_str)
if user_obj.is_valid():
    print(user_obj.validated_data['name'])
    print(user_obj.validated_data['age'])