Python 序列化/反序列化自定义类型

内置json模块对于Python内置类型序列化的描述

    """Extensible JSON <http://json.org> encoder for Python data structures.

    Supports the following objects and types by default:

    +-------------------+---------------+
    | Python            | JSON          |
    +===================+===============+
    | dict              | object        |
    +-------------------+---------------+
    | list, tuple       | array         |
    +-------------------+---------------+
    | str               | string        |
    +-------------------+---------------+
    | int, float        | number        |
    +-------------------+---------------+
    | True              | true          |
    +-------------------+---------------+
    | False             | false         |
    +-------------------+---------------+
    | None              | null          |
    +-------------------+---------------+

    To extend this to recognize other objects, subclass and implement a
    ``.default()`` method with another method that returns a serializable
    object for ``o`` if possible, otherwise it should call the superclass
    implementation (to raise ``TypeError``).

    """

内置json模块对于Python内置类型反序列化的描述

    """Simple JSON <http://json.org> decoder

    Performs the following translations in decoding by default:

    +---------------+-------------------+
    | JSON          | Python            |
    +===============+===================+
    | object        | dict              |
    +---------------+-------------------+
    | array         | list              |
    +---------------+-------------------+
    | string        | str               |
    +---------------+-------------------+
    | number (int)  | int               |
    +---------------+-------------------+
    | number (real) | float             |
    +---------------+-------------------+
    | true          | True              |
    +---------------+-------------------+
    | false         | False             |
    +---------------+-------------------+
    | null          | None              |
    +---------------+-------------------+

    It also understands ``NaN``, ``Infinity``, and ``-Infinity`` as
    their corresponding ``float`` values, which is outside the JSON spec.

    """

 分别使用pickle和json模块来实现自定义类型的序列化和反序列化

class Person():
    """人类"""
    # __slots__ = ['age']
    # __dict__ = ['age', 'name']
    _age: int = 0

    def __init__(self, age, name='eason'):
        # json.JSONEncoder.__init__(self, skipkeys=True)
        self.age = age
        self.name = name
        # self.name = name

    # def __dir__(self):
    #     return ['age', 'name']

    @property
    def age(self) -> int:
        return self._age

    @age.setter
    def age(self, age: int):
        print('set age')
        if age <= 0:
            raise ValueError('age')
        self._age = age

    def hello(self):
        print('==============hello-locals===============')
        print(locals())

import pickle
import json


from demo.src.models.person import Person
# import demo.src.models.person.Person


class PersonJSONEncoder(json.JSONEncoder):
    def default(self, o: Person):
        # 返回字典类型
        return {"name": o.name, "age": o.age}

    # def encode(self, o: Person):
    #     # 直接返回字典，
    #     return str({"age": o.age, "name": o.name})


class PersonJSONDecoder(json.JSONDecoder):
    def decode(self, s: str):
        obj_dict = json.loads(s)
        # return Person(obj_dict['age'], obj_dict['age'])
        return Person(**obj_dict)







p = Person(28, 'wjchi')

# bytes
# p_bytes = pickle.dumps(p)
# print(type(p_bytes), p_bytes)
# p_obj = pickle.loads(p_bytes)
# print(type(p_obj), p_obj.age)

# string

# p_str = json.dumps(p, default=lambda obj: obj.__dict__)
# print(type(p_str), p_str)
# p_dict = json.loads(p_str)
# print(type(p_dict), p_dict['age'])

p_str = json.dumps(p, cls=PersonJSONEncoder)
print(type(p_str), p_str)
p_dict = json.loads(p_str)
# print(type(p_dict), p_dict['age'])
# p_obj = json.loads(p_str, cls=PersonJSONDecoder)
p_obj = Person(**p_dict)
print(type(p_obj), p_obj.age)