Python: Save Object Attributes to Config File Recursively based on a Data Map

config.py

from typing import Callable, TypeVar
from io import FileIO

T = TypeVar("T")

def replace_value(data: dict, data_object: object) -> dict:
    result = data
    for k, v in data.items():
        if isinstance(v, dict):
            result[k] = replace_value(v, data_object)
        else:
            result[k] = getattr(data_object, k)
    return result

def save(data_map: dict, data_object: T, dump: Callable, file: FileIO):
    data = replace_value(data_map, data_object)
    dump(data, file)

def apply_value(data_map: dict, data: dict, data_object: object):
    for k, v in data_map.items():
        if isinstance(v, dict):
            return apply_value(v, data[k], data_object)
        else:
            setattr(data_object, k, v)
            return data_object

def load(data_map: dict, data_object: T, _load: Callable, file: FileIO) -> T:
    data = _load(file)
    return apply_value(data_map, data, data_object)

test.py

import config

import json
import toml
import yaml

from pathlib import Path

testfile_json_path = Path(__file__).parent / "config.json"
testfile_toml_path = Path(__file__).parent / "config.toml"
testfile_yaml_path = Path(__file__).parent / "config.yaml"


data_map = {
    "x": {
        "x_a": "y_a",
        "x_b": "y_b"
    }
}

class TestObject:
    def __init__(self) -> None:
        self.x_a = "A"
        self.x_b = "B"

    def __str__(self) -> str:
        return f"x_a = { self.x_a }, x_b = { self.x_b }"

if __name__ == "__main__":
    test_object = TestObject()
    with open(testfile_json_path, "w") as f:
        config.save(data_map, test_object, json.dump, f)
    with open(testfile_toml_path, "w") as f:
        config.save(data_map, test_object, toml.dump, f)
    with open(testfile_yaml_path, "w") as f:
        config.save(data_map, test_object, yaml.dump, f)

    with open(testfile_json_path, "r") as f:
        print(config.load(data_map, test_object, json.load, f))
    with open(testfile_toml_path, "r") as f:
        print(config.load(data_map, test_object, toml.load, f))
    with open(testfile_yaml_path, "r") as f:
        print(config.load(data_map, test_object, yaml.safe_load, f))