https://docs.python.org/zh-cn/3/library/dataclasses.html
https://peps.python.org/pep-0526/
https://peps.python.org/pep-0557/
dataclass
简单示例
from dataclasses import dataclass@dataclass
class User:name: strage: intif __name__ == '__main__':response_json = {'name': 'python', 'age': 32}user = User(**response_json)print(user.name, user.age) # python 32
不用使用 dataclass
也可以
class User:def __init__(self, name: str, age: int):self.name = nameself.age = ageif __name__ == '__main__':response_json = {'name': 'python', 'age': 32}user = User(**response_json)print(user.name, user.age)
User
显得稍显麻烦,不过这里很简单,倒也无所谓。
dataclass
优势
dataclass
比直接使用class
书写更简洁, 看起来一目了然dataclass
自动实现实用方法,比如__repr__
Pycharm
的完全代码提示
dataclass
的不足
不支持嵌套
from dataclasses import dataclass@dataclass
class Info:sex: strphone: straddress: str = None@dataclass
class User:name: strage: intinfo: Info = Noneif __name__ == '__main__':response_json = {'name': 'python','age': 32,'info': {'sex': '','phone': '','address': 'https://python.org/'},}user = User(**response_json)# 显然这里我们期望的不是 dictassert isinstance(user.info, dict)
不支持扩展字段
from dataclasses import dataclass@dataclass
class User:name: strage: intif __name__ == '__main__':response_json = {'name': 'python','age': 32,'address': 'https://python.org/'}# TypeError: __init__() got an unexpected keyword argument 'address'user = User(**response_json)
使用 datclass
库弥补这些不足
https://github.com/foyoux/datclass
pip install datclass
datclass
简单示例
from dataclasses import dataclassfrom datclass import DatClass@dataclass
class Info(DatClass):sex: strphone: straddress: str = None@dataclass
class User(DatClass):name: strage: intinfo: Info = Noneif __name__ == '__main__':response_json = {'name': 'python','age': 32,'info': {'sex': '','phone': '','address': 'https://python.org/','field': 'extra'},}user = User(**response_json)assert isinstance(user.info, Info)assert isinstance(user.info, Info)print(user.info.address) # https://python.org/
datclass
附带一个命令行命令用以自动生成 DatClass
→ datclass