Example of seperation of concepts

dao.py

from pymongo import MongoClient


class BaseDAO:
    def create(self):
        ...

    def get(self):
        ...


class MongoDAO(BaseDAO):
    def __init__(self):
        client = MongoClient("mongodb://localhost:21018")
        self.db = client.example

    def create(self, data: dict):
        self.db.posts.insert_one(data)

    def get(self):
        return list(self.db.posts.find({}))

dto.py

from typing_extensions import Self
from dataclasses import dataclass, field


@dataclass
class Post:
    title: str = field()
    data: str = field()

    @classmethod
    def from_dict(cls, data: dict) -> Self:
        return cls(title=data["title"], data=data["data"])

logic.py

class PostsLogic:
    def __init__(self, posts_collection: list[dict]) -> None:
        self.posts_collection = posts_collection

    def get_posts(self) -> list[dict]:
        posts: list[dict] = []

        for post in self.posts_collection:
            post["data"] += f" {datetime.now()}"
            if datetime.now() > datetime(year=2022, month=8, day=17):
                post["outdated"] = True
            posts.append(post)

        return posts

service.py

from logic import PostsLogic
from dao import BaseDAO
from dto import Post


class Service:
    def __init__(self, dao: BaseDAO):
        self.dao = dao

    def get_posts_list(self) -> list[Post]:
        posts_collection = self.dao.get()

        logic = PostsLogic(posts_collection)

        posts = logic.get_posts()

        return Post.from_dict(posts)