python - 如何使用存储在单独模块中的错误代码

Question

在 errors.py 模块中，我定义了几个错误，例如:

INCORRECT_USERNAME = -2417
INCORRECT_PASSWORD = -2426
PASSWORD_EXPIRED = -2430
ACCOUNT_DISABLED = -2431

现在，我将此模块导入到另一个 Python 脚本中并检查错误代码是否匹配:

import errors 


def get_error_name():
    returned_code = some_function(some_argument)

    if returned_code == errors.INCORRECT_USERNAME:
        return "INCORRECT_USERNAME"
    elif returned_code == errors.INCORRECT_PASSWORD:
        return "INCORRECT_PASSWORD"
    elif returned_code == errors.PASSWORD_EXPIRED:
        return "PASSWORD_EXPIRED"
    elif returned_code == errors.ACCOUNT_DISABLED:
        return "ACCOUNT_DISABLED"

生成的代码似乎过于冗余或过于冗长。有没有更简洁的方法来返回错误消息的字符串值？

Answer 1

这似乎是 Enum 的一个很好的用例:

# errors.py
import enum

class Error(enum.IntEnum):
    INCORRECT_USERNAME = -2417
    INCORRECT_PASSWORD = -2426
    PASSWORD_EXPIRED   = -2430
    ACCOUNT_DISABLED   = -2431



# another_script.py
import errors 

def get_error_name():
    returned_code = some_function(some_argument)
    return errors.Error(returned_code).name

或者，如果您想返回的不仅仅是错误名称，您可以考虑使用 namedtuple :

# errors.py
import collections

Error = collections.namedtuple('Error', ['name', 'msg'])
all_errors = {
    -2417: Error('INCORRECT_USERNAME', 'The provided username was incorrect'),
    -2426: Error('INCORRECT_PASSWORD', 'The provided password was incorrect'),
    -2430: Error('PASSWORD_EXPIRED',   'Your password has expired'),
    -2431: Error('ACCOUNT_DISABLED',   'Your account is disabled'),
}



# another_script.py
import errors 

def get_error_name():
    returned_code = some_function(some_argument)
    return errors.all_errors[returned_code].name

def get_error_msg():
    returned_code = some_function(some_argument)
    return errors.all_errors[returned_code].msg