Python class 中使用@dataclass 创建的实例属性赋值

Question

我刚开始使用@dataclass 装饰器。这是我没有数据类的实现

class Myclass:

    def __init__(self, path: str = None, company_name: List = None):

        self.path = path
        self.company_name = company_name

        if path is not None:
            with open(self.path, 'r') as f:
                self.data = yaml.load(f, Loader=yaml.FullLoader)
        else:
            self.data = {'company': self.company_name}

所以在这里，我正在做一个实例属性赋值。

c = Myclass(path = '/home/akash/project/stock-analysis/data/sample_company.yaml')
c.data
>>>{'company': ['ADANIGREEN', 'HDFCAMC', 'WHIRLPOOL', 'APLAPOLLO', 'LALPATHLAB']}

我管理的@dataclass 等价物是

@dataclass
class Myclass:
    path: str=None
    company_name: List=None
        
    def __post_init__(self):
        if self.path is not None:
            with open(self.path, 'r') as f:
                self.data = yaml.load(f, Loader=yaml.FullLoader)
        else:
            self.data = {'company': self.company_name}

它给出了完全相同的输出（这是预期的）

c = Myclass(path = '/home/akash/project/stock-analysis/data/sample_company.yaml')
c.data
>>>{'company': ['ADANIGREEN', 'HDFCAMC', 'WHIRLPOOL', 'APLAPOLLO', 'LALPATHLAB']}

那么，我的做法对吗？

Answer 1

如果您想将 data 作为一个字段包含在内，您可以使用 field(init=False) 对其进行初始化，以表明它的值不是 __init__ 的参数：

from dataclasses import dataclass, field
from typing import List, Dict
import yaml

@dataclass
class Myclass:
    path: str = None
    company_name: List[str] = None
    data: Dict[str, List[str]] = field(init=False)
        
    def __post_init__(self):
        if self.path is not None:
            with open(self.path, 'r') as f:
                self.data = yaml.load(f, Loader=yaml.FullLoader)
        else:
            self.data = {'company': self.company_name}

Python class 中使用@dataclass 创建的实例属性赋值

Python instance attribute assignment in class created using @dataclass

python

python-3.x

python-dataclasses

python-class