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?
Dacite也可能是您的解决方案,它支持以下功能:
嵌套结构
(基本)类型检查
可选字段(即typing.Optional)
工会
向前引用
集合
自定义类型钩子
https://pypi.org/project/dacite/
from dataclasses import dataclass
from dacite import from_dict
@dataclass
class User:
name: str
age: int
is_active: bool
data = {
'name': 'John',
'age': 30,
'is_active': True,
}
user = from_dict(data_class=User, data=data)
assert user == User(name='John', age=30, is_active=True)
如果你使用的是Python 3.5+,你可以使用json来序列化和反序列化到普通的旧Python对象:
import jsons
response = request.POST
# You'll need your class attributes to match your dict keys, so in your case do:
response['id'] = response.pop('user_id')
# Then you can load that dict into your class:
user = jsons.load(response, FbApiUser)
user.save()
你也可以让FbApiUser从jsons继承。JsonSerializable更优雅:
user = FbApiUser.from_json(response)
如果你的类由Python默认类型组成,比如字符串、整数、列表、日期时间等,这些例子就可以工作。不过,jsons lib需要自定义类型的类型提示。
你可以试试这个:
class User(object):
def __init__(self, name, username):
self.name = name
self.username = username
import json
j = json.loads(your_json)
u = User(**j)
只需创建一个新对象,并将参数作为映射传递。
你也可以有一个带有对象的JSON:
import json
class Address(object):
def __init__(self, street, number):
self.street = street
self.number = number
def __str__(self):
return "{0} {1}".format(self.street, self.number)
class User(object):
def __init__(self, name, address):
self.name = name
self.address = Address(**address)
def __str__(self):
return "{0} ,{1}".format(self.name, self.address)
if __name__ == '__main__':
js = '''{"name":"Cristian", "address":{"street":"Sesame","number":122}}'''
j = json.loads(js)
print(j)
u = User(**j)
print(u)
既然没有人给出了和我一样的答案,我就把它贴在这里。
这是一个健壮的类,可以轻松地在JSON str和dict之间来回转换,我已经从我的答案复制到另一个问题:
import json
class PyJSON(object):
def __init__(self, d):
if type(d) is str:
d = json.loads(d)
self.from_dict(d)
def from_dict(self, d):
self.__dict__ = {}
for key, value in d.items():
if type(value) is dict:
value = PyJSON(value)
self.__dict__[key] = value
def to_dict(self):
d = {}
for key, value in self.__dict__.items():
if type(value) is PyJSON:
value = value.to_dict()
d[key] = value
return d
def __repr__(self):
return str(self.to_dict())
def __setitem__(self, key, value):
self.__dict__[key] = value
def __getitem__(self, key):
return self.__dict__[key]
json_str = """... JSON string ..."""
py_json = PyJSON(json_str)
改进lovasoa非常好的答案。
如果你正在使用python 3.6+,你可以使用:
PIP安装棉花糖-enum和
PIP安装棉花糖数据类
它简单且类型安全。
你可以在string-json中转换你的类,反之亦然:
从对象到字符串Json:
from marshmallow_dataclass import dataclass
user = User("Danilo","50","RedBull",15,OrderStatus.CREATED)
user_json = User.Schema().dumps(user)
user_json_str = user_json.data
从String Json到Object:
json_str = '{"name":"Danilo", "orderId":"50", "productName":"RedBull", "quantity":15, "status":"Created"}'
user, err = User.Schema().loads(json_str)
print(user,flush=True)
类定义:
class OrderStatus(Enum):
CREATED = 'Created'
PENDING = 'Pending'
CONFIRMED = 'Confirmed'
FAILED = 'Failed'
@dataclass
class User:
def __init__(self, name, orderId, productName, quantity, status):
self.name = name
self.orderId = orderId
self.productName = productName
self.quantity = quantity
self.status = status
name: str
orderId: str
productName: str
quantity: int
status: OrderStatus