带有私有字段的json转储 [英] json dumps with private fields

问题描述

我想将用户序列化为json.用户只有私人字段.

I would like to serialize users into json. User has only private fields.

user.py

class User:
    def __init__(self, id, name):
        self. set_id(id)
        self.set_name(name)

    def set_id(self, id):
        self.__id = id

    def set_name(self, name):
        self.__name = name

json_encoder.py ，没有它，json.dumps不起作用.

json_encoder.py, without it json.dumps does not work.

from json import JSONEncoder


class JsonEncoder(JSONEncoder):
    def default(self, o):
        return o.__dict__

user_app.py

import json
from json_encoder import JsonEncoder
from user import User

def main():
    users = build_users(names) # a function that returns list of users
    users_json = json.dumps(users, indent=4, sort_keys=True, cls=JsonEncoder)
    print(users_json)


if __name__ == '__main__':
    main()

它打印

[
    {
        "_User__id": 0,
        "_User__name": "Alex"
    },
    {
        "_User__id": 1,
        "_User__name": "John"
    }
]

哪个好.但是，我希望将私有字段用作字段名-不带类名前缀.

Which is almost good. I would like, however, to have private fields as field names - without class name prefix.

[
    {
        "id": 0,
        "name": "Alex"
    }
]

是否有注释，或者我应该编写自定义帮助程序来自定义json输出.

Is there annotation, or should I write custom helper to customize json output.

顺便说一句，在python中创建私有字段是一种好习惯吗?我来自Java世界，在这里我们更喜欢私有字段.

By the way, is it a good practice to make private fields in python? I come from Java world, where we do prefer private fields.

如何使可序列化的JSON类部分回答了我的问题.如何使用漂亮的属性名称对其进行序列化，请参见输出示例，但我仍然需要了解更多信息.我不知道如何自定义 JsonEncoder .我发布了答案.

How to make a class JSON serializable partially answers my question. How to serialize it with beautiful properties names, see example of my output, I still have to learn more. I did not know how customize JsonEncoder. I posted my answer.

推荐答案

感谢 jasonharper 到目前为止，我发现<有关属性和设置器的一个href ="https://www.python-course.eu/python3_properties.php" rel ="nofollow noreferrer">示例现在，我知道如何在python中封装.

Thanks to jasonharper So far, I found example about properties and setters Now I know how to do encapsulation in python.

user.py

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

    @property
    def id(self):
        return self.__id

    @id.setter
    def id(self, id):
        self.__id = id

    @property
    def name(self):
        return self.__name

    @name.setter
    def name(self, name):
        self.__name = name

接下来，我需要将其序列化为JSON .

json_encoder.py

from json import JSONEncoder


def beautify_key(str):
    index = str.index('__')
    if index <= 0:
        return str

    return str[index + 2:]


class JsonEncoder(JSONEncoder):

    def default(self, o):
        return {beautify_key(k): v for k, v in vars(o).items()}

现在输出对我来说是正确的.

Now the output is correct for me.

[
    {
        "id": 0,
        "name": "Alex"
    },
    {
        "id": 1,
        "name": "John"
    }
]

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