Python - set class var from a private static method

Question

I've written the following base static class in python:

from abc import ABC,abstractmethod

import typing
from main_module import utils


class BaseCLS(ABC):
    credentials = None # <--- I want to set this var
    def __init_session(caller) -> None:
        credentials = utils.get_creds() # <--- not the right var

    @staticmethod
    @__init_session
    def process(path: str) -> None:
        raise NotImplementedError

The base class private method __init_session is triggered by a decorator each time process is called. I'm trying to set the credentials class var from within the private method with no luck. How can I achieve my goal?

Answer 1

If you want to set the class variable in derived classes, the following would work.

from abc import ABC,abstractmethod
import typing
import random

class BaseCLS(ABC):
    credentials = None # <--- I want to set this var

    def __init_session(caller) -> None:
        def inner(cls, path):
            # credentials = utils.get_creds()
            cls.credentials = random.random()
            caller(cls, path)
        return inner

    @classmethod # <--- changed to classmethod
    @__init_session
    def process(cls, path: str) -> None:
      pass

class B(BaseCLS):
  pass

class C(BaseCLS):
  pass


B.process("a")
C.process("b")

print(B.credentials)
print(C.credentials)