configer.py

from json import load, dump
from os import access, F_OK


default = {
    "lang": "en"
}


class Config:
    def __init__(self):
        if access('config.json', F_OK):
            with open('config.json', encoding='utf-8') as file:
                self.data = load(file)
        else:
            self.data = default
            self.update()

    def __getitem__(self, key):
        return self.data[key]

    def __setitem__(self, key, value):
        self.data[key] = value
        self.update()

    def update(self):
        with open('config.json', 'w', encoding='utf-8') as file:
            dump(self.data, file)


config = Config()