## Lifespan

You can define this *startup* and *shutdown* logic using the `lifespan` parameter of the `FastAPI` app, and a "context manager" (I'll show you what that is in a second).

Let's start with an example and then see it in detail.

We create an async function `lifespan()` with `yield` like this:

{* ../../docs_src/events/tutorial003.py hl[16,19] *}

        authorization = request.headers.get("Authorization")
        if not authorization:
            if self.auto_error:
                raise HTTPException(
                    status_code=HTTP_403_FORBIDDEN, detail="Not authenticated"
                )
            else:
                return None
        return authorization


class OAuth2PasswordBearer(OAuth2):
    """

    return client


@needs_py39
def test_get_no_item(client: TestClient):
    response = client.get("/items/foo")
    assert response.status_code == 404, response.text
    assert response.json() == {"detail": "Item not found, there's only a plumbus here"}


@needs_py39
def test_get(client: TestClient):
    response = client.get("/items/plumbus")
    assert response.status_code == 200, response.text

    assert response.json() == {"username": "secret"}


def test_security_api_key_no_key():
    response = client.get("/users/me")
    assert response.status_code == 403, response.text
    assert response.json() == {"detail": "Not authenticated"}


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",

def test_security_http_base_no_credentials():
    response = client.get("/users/me")
    assert response.status_code == 403, response.text
    assert response.json() == {"detail": "Not authenticated"}


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",

        raise InternalError(
            f"The portal gun is too dangerous to be owned by {username}"
        )
    if item_id != "plumbus":
        raise HTTPException(
            status_code=404, detail="Item not found, there's only a plumbus here"
        )

```

</div>

Wenn Sie dann zu den URLs unter `/openapi.json`, `/docs` oder `/redoc` gehen, erhalten Sie lediglich einen `404 Not Found`-Fehler, wie:

```JSON
{
    "detail": "Not Found"
}

        Element section = document.createElement("section");
        parent.appendChild(section);
        section.setAttribute("id", blockDoc.getId());
        section.setAttribute("role", "detail");

        Element title = document.createElement("title");
        section.appendChild(title);
        Element literal = document.createElement("literal");
        title.appendChild(literal);

        current_password_bytes, correct_password_bytes
    )
    if not (is_correct_username and is_correct_password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect username or password",
            headers={"WWW-Authenticate": "Basic"},
        )
    return credentials.username


@app.get("/users/me")

    response = client.get(
        "/users/me", headers={"Authorization": "Other invalidauthorization"}
    )
    assert response.status_code == 403, response.text
    assert response.json() == {"detail": "Invalid authentication credentials"}


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {