[Python] How does one ignore extra arguments passed to a dataclass?

I'd like to create a config dataclass in order to simplify whitelisting of and access to specific environment variables (typing os.environ['VAR_NAME'] is tedious relative to config.VAR_NAME). I therefore need to ignore unused environment variables in my dataclass's __init__ function, but I don't know how to extract the default __init__ in order to wrap it with, e.g., a function that also includes *_ as one of the arguments.

import os
from dataclasses import dataclass

@dataclass
class Config:
VAR_NAME_1: str
VAR_NAME_2: str

config = Config(**os.environ)


Running this gives me TypeError: __init__() got an unexpected keyword argument 'SOME_DEFAULT_ENV_VAR'.

Continue reading...