from collections.abc import Generator
from contextlib import contextmanager
from typing import Annotated, Any

import pytest
from fastapi import Depends, FastAPI
from fastapi.responses import StreamingResponse
from fastapi.testclient import TestClient


class Session:
    def __init__(self) -> None:
        self.data = ["foo", "bar", "baz"]
        self.open = True

    def __iter__(self) -> Generator[str, None, None]:

from fastapi import FastAPI

app = FastAPI()

items = {}


@app.on_event("startup")
async def startup_event():
    items["foo"] = {"name": "Fighters"}
    items["bar"] = {"name": "Tenders"}


@app.get("/items/{item_id}")
async def read_items(item_id: str):

이 경우 함수 매개변수 `q`는 선택적이며 기본값으로 `None` 값이 됩니다.

/// check | 확인

**FastAPI**는 `item_id`가 경로 매개변수이고 `q`는 경로 매개변수가 아닌 쿼리 매개변수라는 것을 알 정도로 충분히 똑똑합니다.

///

/// note | 참고

FastAPI는 `q`가 `= None`이므로 선택적이라는 것을 인지합니다.

`Union[str, None]`에 있는 `Union`은 FastAPI(FastAPI는 `str` 부분만 사용합니다)가 사용하는게 아니지만, `Union[str, None]`은 편집기에게 코드에서 오류를 찾아낼 수 있게 도와줍니다.

///

## 쿼리 매개변수 형변환

These details are useful mainly if you had a FastAPI application older than 0.121.0 and you are facing issues with dependencies with `yield`.

///

Dependencies with `yield` have evolved over time to account for the different use cases and to fix some issues, here's a summary of what has changed.

### Dependencies with `yield` and `scope` { #dependencies-with-yield-and-scope }

from typing import Union

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(
    hidden_query: Union[str, None] = Query(default=None, include_in_schema=False),
):
    if hidden_query:
        return {"hidden_query": hidden_query}
    else:

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: str | None = Query(default=None, min_length=3, max_length=50)):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

import time

from fastapi import FastAPI, Request

app = FastAPI()


@app.middleware("http")
async def add_process_time_header(request: Request, call_next):
    start_time = time.perf_counter()
    response = await call_next(request)
    process_time = time.perf_counter() - start_time
    response.headers["X-Process-Time"] = str(process_time)

Yani yumurta mı tavukdan, tavuk mu yumurtadan gibi ilk `async` fonksiyonu nasıl çağırılır?

**FastAPI** ile çalışıyorsanız bunun için endişelenmenize gerek yok, çünkü bu "ilk" fonksiyon sizin *path fonksiyonunuz* olacak ve FastAPI doğru olanı nasıl yapacağını bilecek.

# URL-адреса метаданных и документации { #metadata-and-docs-urls }

Вы можете настроить несколько конфигураций метаданных в вашем **FastAPI** приложении.

## Метаданные для API { #metadata-for-api }

Вы можете задать следующие поля, которые используются в спецификации OpenAPI и в UI автоматической документации API:

| Параметр | Тип | Описание |
|------------|------|-------------|
| `title` | `str` | Заголовок API. |

from pydantic import BaseModel, SecretStr
from pydantic_settings import BaseSettings

github_graphql_url = "https://api.github.com/graphql"


prs_query = """
query Q($after: String) {
  repository(name: "fastapi", owner: "fastapi") {
    pullRequests(first: 100, after: $after) {
      edges {
        cursor
        node {
          number
          labels(first: 100) {
            nodes {
              name
            }