## ✍ 📋 🔢

✍ 🔢 🏃 🖥 📋.

⚫️ 🐩 🔢 👈 💪 📨 🔢.

⚫️ 💪 `async def` ⚖️ 😐 `def` 🔢, **FastAPI** 🔜 💭 ❔ 🍵 ⚫️ ☑.

👉 💼, 📋 🔢 🔜 ✍ 📁 (⚖ 📨 📧).

& ✍ 🛠️ 🚫 ⚙️ `async` & `await`, 👥 🔬 🔢 ⏮️ 😐 `def`:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## 🚮 🖥 📋

🔘 👆 *➡ 🛠️ 🔢*, 🚶‍♀️ 👆 📋 🔢 *🖥 📋* 🎚 ⏮️ 👩‍🔬 `.add_task()`:

def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>⚖️ ⚙️ <code>async def</code>...</summary>

🚥 👆 📟 ⚙️ `async` / `await`, ⚙️ `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():
    return {"Hello": "World"}

    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>או השתמשו ב - <code>async def</code>...</summary>

אם הקוד שלכם משתמש ב - `async` / `await`, השתמשו ב - `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():

In diesem Fall schreibt die Taskfunktion in eine Datei (den Versand einer E-Mail simulierend).

Und da der Schreibvorgang nicht `async` und `await` verwendet, definieren wir die Funktion mit normalem `def`:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Den Hintergrundtask hinzufügen

{* ../../docs_src/app_testing/tutorial001.py hl[2,12,15:18] *}

/// tip

Notice that the testing functions are normal `def`, not `async def`.

And the calls to the client are also normal calls, not using `await`.

This allows you to use `pytest` directly without complications.

///

/// note | Technical Details

You could also use `from starlette.testclient import TestClient`.

    As always, in FastAPI you can combine `def` and `async def` as needed.

    If you need a refresher about when to use which, check out the section _"In a hurry?"_ in the docs about [`async` and `await`](../async.md#in-a-hurry){.internal-link target=_blank}.

9. This *path operation function* is not returning dataclasses (although it could), but a list of dictionaries with internal data.

    Wenn Sie eine Auffrischung darüber benötigen, wann welche Anwendung sinnvoll ist, lesen Sie den Abschnitt „In Eile?“ in der Dokumentation zu [`async` und `await`](../async.md#in-eile){.internal-link target=_blank}.

9. Diese *Pfadoperation-Funktion* gibt keine Datenklassen zurück (obwohl dies möglich wäre), sondern eine Liste von Dictionarys mit internen Daten.

В нашем примере фоновая задача будет вести запись в файл (симулируя отправку письма).

Так как операция записи не использует `async` и `await`, мы определим ее как обычную `def`:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Добавление фоновой задачи

        };

        InputStreamThread thread = new InputStreamThread(is, StandardCharsets.UTF_8, 100, callback);
        thread.start();

        assertTrue("Should process all lines within timeout", latch.await(3, TimeUnit.SECONDS));

        thread.join(1000);

        assertEquals("All lines should be processed", 5000, receivedLines.size());
        assertEquals("First line", "Line number 0", receivedLines.get(0));

    afterStarted.countDown();
    // We do not call awaitHealthy because, due to races, that method may throw an exception.  But
    // we really just want to wait for the thread to be in the failure callback so we wait for that
    // explicitly instead.
    failEnter.await();
    assertFalse("State should be updated before calling listeners", manager.isHealthy());
    // now we want to stop the services.
    Thread stoppingThread =