python - 需要一种方法从 marshmallow 加载函数而不是字典中获取 python 对象，而不使用 post_load 装饰器

Question

class ProfileSchema(Schema):

    id = fields.Integer()
    first_name = fields.String(required=True)
    last_name = fields.String()
    phone = fields.Str()
    email = fields.Email()
    gender = fields.String()
    city = fields.Str()
    state = fields.Str()
    country = fields.Str()
    age = fields.Int()
    id_proof = fields.Str()
    id_number = fields.Str()
    id_kyc_url = fields.Str()
    image_url = fields.Str()
    profile_type = fields.Str()
    country_code = fields.String()

    @validates('gender')
    def validate_gender(self, value):
        """
        validates gender
        :param value:
        :return:
        """
        if value not in genders:
            raise ValidationError('Incorrect gender value it should be either Male or Female')

    @post_load
    def make_profile(self, data):
        """
        make profile obj
        :param data:
        :return:
        """
        return Profile(**data)

在上面的模式中，我使用 post_load 将字典转换为对象。有没有办法在不使用 post_load 装饰器的情况下得到这个？

Answer 1

如果我理解正确的话，你遇到的问题不是 post_load 装饰器，而是维护两个对象定义的冗余。如果是这种情况，您可以使用 namedtuple或dataclasses实现你想要的。您仍然可以在架构上定义 post_load 方法，但不再需要维护第二个类定义。

namedtuple解决方案

from collections import namedtuple

def make_object(class_name, members):
    obj = namedtuple(class_name, ' '.join(members.keys()))
    for k, v in members.items():
        setattr(obj, k, v)
    return obj

数据类解决方案

from dataclasses import make_dataclass

def make_object(class_name, members):
    obj = make_dataclass(class_name, [(k, type(v)) for k,v in members.items()])
    for k, v in members.items():
        setattr(obj, k, v)
    return obj

class ProfileSchema(Schema):

    id = fields.Integer()
    first_name = fields.String(required=True)
    last_name = fields.String()
    phone = fields.Str()
    email = fields.Email()
    gender = fields.String()
    city = fields.Str()
    state = fields.Str()
    country = fields.Str()
    age = fields.Int()
    id_proof = fields.Str()
    id_number = fields.Str()
    id_kyc_url = fields.Str()
    image_url = fields.Str()
    profile_type = fields.Str()
    country_code = fields.String()

    @validates('gender')
    def validate_gender(self, value):
        """
        validates gender
        :param value:
        :return:
        """
        if value not in genders:
            raise ValidationError('Incorrect gender value it should be either Male or Female')

    @post_load
    def make_profile(self, data):
        """
        make profile obj
        :param data:
        :return:
        """
        return make_object(data)