我想将JSON数据转换为Python对象。

我从Facebook API收到JSON数据对象,我想将其存储在数据库中。

我的当前视图在Django (Python)(请求。POST包含JSON):

response = request.POST
user = FbApiUser(user_id = response['id'])
user.name = response['name']
user.username = response['username']
user.save()

这很好,但是如何处理复杂的JSON数据对象呢? 如果我能以某种方式将这个JSON对象转换为易于使用的Python对象,是不是会更好?


当前回答

如果你正在使用python 3.6+,你可以使用棉花糖-数据类。与上面列出的所有解决方案相反,它既简单,又类型安全:

from marshmallow_dataclass import dataclass

@dataclass
class User:
    name: str

user = User.Schema().load({"name": "Ramirez"})

其他回答

这不是一个很难的事情,我看到上面的答案,他们中的大多数在“列表”中有一个性能问题

这段代码比上面的代码快得多

import json 

class jsonify:
    def __init__(self, data):
        self.jsonify = data

    def __getattr__(self, attr):
        value = self.jsonify.get(attr)
        if isinstance(value, (list, dict)):
            return jsonify(value)
        return value

    def __getitem__(self, index):
        value = self.jsonify[index]
        if isinstance(value, (list, dict)):
            return jsonify(value)
        return value

    def __setitem__(self, index, value):
        self.jsonify[index] = value

    def __delattr__(self, index):
        self.jsonify.pop(index)

    def __delitem__(self, index):
        self.jsonify.pop(index)

    def __repr__(self):
        return json.dumps(self.jsonify, indent=2, default=lambda x: str(x))

exmaple

response = jsonify(
    {
        'test': {
            'test1': [{'ok': 1}]
        }
    }
)
response.test -> jsonify({'test1': [{'ok': 1}]})
response.test.test1 -> jsonify([{'ok': 1}])
response.test.test1[0] -> jsonify({'ok': 1})
response.test.test1[0].ok -> int(1)

使用python 3.7,我发现下面的代码非常简单有效。在本例中,将JSON从文件加载到字典中:

class Characteristic:
    def __init__(self, characteristicName, characteristicUUID):
        self.characteristicName = characteristicName
        self.characteristicUUID = characteristicUUID


class Service:
    def __init__(self, serviceName, serviceUUID, characteristics):
        self.serviceName = serviceName
        self.serviceUUID = serviceUUID
        self.characteristics = characteristics

class Definitions:
    def __init__(self, services):
        self.services = []
        for service in services:
            self.services.append(Service(**service))


def main():
    parser = argparse.ArgumentParser(
        prog="BLEStructureGenerator",
        description="Taking in a JSON input file which lists all of the services, "
                    "characteristics and encoded properties. The encoding takes in "
                    "another optional template services and/or characteristics "
                    "file where the JSON file contents are applied to the templates.",
        epilog="Copyright Brown & Watson International"
    )

    parser.add_argument('definitionfile',
                        type=argparse.FileType('r', encoding='UTF-8'),
                        help="JSON file which contains the list of characteristics and "
                             "services in the required format")
    parser.add_argument('-s', '--services',
                        type=argparse.FileType('r', encoding='UTF-8'),
                        help="Services template file to be used for each service in the "
                             "JSON file list")
    parser.add_argument('-c', '--characteristics',
                        type=argparse.FileType('r', encoding='UTF-8'),
                        help="Characteristics template file to be used for each service in the "
                             "JSON file list")

    args = parser.parse_args()
    definition_dict = json.load(args.definitionfile)
    definitions = Definitions(**definition_dict)

修改@DS响应位,从一个文件加载:

def _json_object_hook(d): return namedtuple('X', d.keys())(*d.values())
def load_data(file_name):
  with open(file_name, 'r') as file_data:
    return file_data.read().replace('\n', '')
def json2obj(file_name): return json.loads(load_data(file_name), object_hook=_json_object_hook)

有一点:它不能加载前面有数字的项目。是这样的:

{
  "1_first_item": {
    "A": "1",
    "B": "2"
  }
}

因为“1_first_item”不是一个有效的python字段名。

class SimpleClass:
    def __init__(self, **kwargs):
        for k, v in kwargs.items():
            if type(v) is dict:
                setattr(self, k, SimpleClass(**v))
            else:
                setattr(self, k, v)


json_dict = {'name': 'jane doe', 'username': 'jane', 'test': {'foo': 1}}

class_instance = SimpleClass(**json_dict)

print(class_instance.name, class_instance.test.foo)
print(vars(class_instance))

这里有一个快速而肮脏的json pickle替代方案

import json

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

    def to_json(self):
        return json.dumps(self.__dict__)

    @classmethod
    def from_json(cls, json_str):
        json_dict = json.loads(json_str)
        return cls(**json_dict)

# example usage
User("tbrown", "Tom Brown").to_json()
User.from_json(User("tbrown", "Tom Brown").to_json()).to_json()