decorator for properties, that will try to get ENV variable or return value from property method.

env_property_example.py

import os
from typing import Optional, Any


def get_env_var(var_name: str) -> Optional[str]:
    return os.environ.get(var_name)


def env_prop(fn=None, name=None):
    def env_prop_decorator(func):
        env_name = name or func.__name__.upper()

        def wrapper(*args: Any, **kwargs: Any) -> Optional[str]:
            return get_env_var(env_name) or func(*args, **kwargs)

        return property(wrapper)

    if fn is None:
        return env_prop_decorator
    return env_prop_decorator(fn)


# example
class LocalConf:
    @env_prop
    def debug(self) -> bool:
        return True

    @env_prop
    def host(self) -> str:
        return '0.0.0.0'

    @env_prop
    def port(self) -> int:
        return 80