In Python, you can create Context Managers by <a href="https://docs.python.org/3/reference/datamodel.html#context-managers" class="external-link" target="_blank">creating a class with two methods: `__enter__()` and `__exit__()`</a>.

You can also use them inside of **FastAPI** dependencies with `yield` by using
`with` or `async with` statements inside of the dependency function:

```Python hl_lines="1-9  13"

            async with AsyncExitStack() as async_exit_stack:
                solved_result = await solve_dependencies(
                    request=request,
                    dependant=dependant,
                    body=body,
                    dependency_overrides_provider=dependency_overrides_provider,
                    async_exit_stack=async_exit_stack,
                )

* **요청**을 응용 프로그램의 *경로 작동*으로 전달하여 처리합니다.
* 애플리케이션의 *경로 작업*에서 생성한 **응답**를 받습니다.
* **응답** 또는 다른 필요한 코드를 실행시키는 동작을 할 수 있습니다.
* **응답**를 반환합니다.

!!! note "기술 세부사항"
    만약 `yield`를 사용한 의존성을 가지고 있다면, 미들웨어가 실행되고 난 후에 exit이 실행됩니다.

    만약 (나중에 문서에서 다룰) 백그라운드 작업이 있다면, 모든 미들웨어가 실행되고 *난 후에* 실행됩니다.

## 미들웨어 만들기

미들웨어를 작성하기 위해서 함수 상단에 `@app.middleware("http")` 데코레이터를 사용할 수 있습니다.

미들웨어 함수는 다음 항목들을 받습니다:

* `request`.

    logging.info(f"PR #{pr.number} has labels: {label_strs}")
    if not langs or lang_all_label not in label_strs:
        logging.info(f"PR #{pr.number} doesn't seem to be a translation PR, skipping")
        sys.exit(0)

    # Generate translation map, lang ID to discussion
    discussions = get_graphql_translation_discussions(settings=settings)
    lang_to_discussion_map: Dict[str, AllDiscussionsDiscussionNode] = {}

    if (
        people_old_content == new_people_content
        and github_sponsors_old_content == new_github_sponsors_content
    ):
        logging.info("The FastAPI People data hasn't changed, finishing.")
        sys.exit(0)
    people_path.write_text(new_people_content, encoding="utf-8")
    github_sponsors_path.write_text(new_github_sponsors_content, encoding="utf-8")
    logging.info("Setting up GitHub Actions git user")

This was designed this way mainly to allow using the same objects "yielded" by dependencies inside of background tasks, because the exit code would be executed after the background tasks were finished.

        logging.error(f"Error parsing event file: {e.errors()}")
        sys.exit(0)
    use_pr: Union[PullRequest, None] = None
    for pr in repo.get_pulls():
        if pr.head.sha == event.workflow_run.head_commit.id:
            use_pr = pr
            break
    if not use_pr:
        logging.error(f"No PR found for hash: {event.workflow_run.head_commit.id}")
        sys.exit(0)
    github_headers = {

    This way we make sure the database session is always closed after the request. Even if there was an exception while processing the request.

    But you can't raise another exception from the exit code (after `yield`). See more in [Dependencies with `yield` and `HTTPException`](dependencies/dependencies-with-yield.md#dependencies-with-yield-and-httpexception){.internal-link target=_blank}