class_get_attr_name_as_string.py

class_get_attr_name_as_string.py

#!/usr/bin/env python3


class cstr(str):
    """to avoid string to be 'interned'"""


class Meta(type):
    def __new__(cls, name, bases, attrs):
        for k, v in attrs.items():
            if not k.startswith("__") and type(v) == str:
                attrs[k] = cstr(v)
        return super().__new__(cls, name, bases, attrs)


class BaseError(metaclass=Meta):
    @staticmethod
    def _get_key_value(x):
        for k, v in ERROR.__dict__.items():
            if v is x:
                return k.lower()


class ERROR(BaseError):
    USER_NOT_FOUND = "the-same-value"
    PROVIDER_NOT_FOUND = "the-same-value"


assert ERROR._get_key_value(ERROR.USER_NOT_FOUND) == "user_not_found"
assert ERROR._get_key_value(ERROR.PROVIDER_NOT_FOUND) == "provider_not_found"