dependencies.py

from fastapi import FastAPI, Depends
from pydantic import BaseModel


class Comment(BaseModel):
    username: str
    content: str


app = FastAPI()


database = {
    "articles": {
        1: {
            "title": "Top 3 Reasons to Start Using FastAPI Now",
            "comments": []
        }
    }
}


def get_database():
    return database


@app.post("/articles/{article_id}/comments")
def post_comment(article_id: int, comment: Comment, database = Depends(get_database)):
    database["articles"][article_id]["comments"].append(comment)
    return {"msg": "comment posted!"}