In this case, it is an `async` function.

---

You could also define it as a normal function instead of `async def`:

{* ../../docs_src/first_steps/tutorial003.py hl[7] *}

/// note

If you don't know the difference, check the [Async: *"In a hurry?"*](../async.md#in-a-hurry){.internal-link target=_blank}.

///

It is just a standard function that can receive parameters.

It can be an `async def` or normal `def` function, **FastAPI** will know how to handle it correctly.

In this case, the task function will write to a file (simulating sending an email).

And as the write operation doesn't use `async` and `await`, we define the function with normal `def`:

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

É apenas uma função padrão que pode receber parâmetros.

Pode ser uma função `async def` ou `def` normal, o **FastAPI** saberá como lidar com isso corretamente.

Nesse caso, a função de tarefa gravará em um arquivo (simulando o envio de um e-mail).

E como a operação de gravação não usa `async` e `await`, definimos a função com `def` normal:

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

W tym przypadku jest to funkcja "asynchroniczna".

---

Możesz również zdefiniować to jako normalną funkcję zamiast `async def`:

{* ../../docs_src/first_steps/tutorial003.py hl[7] *}

/// note

Jeśli nie znasz różnicy, sprawdź [Async: *"In a hurry?"*](../async.md#in-a-hurry){.internal-link target=_blank}.

///

### Krok 5: zwróć zawartość

import org.codelibs.fess.sso.SsoAuthenticator;
import org.codelibs.fess.util.ComponentUtil;
import org.dbflute.optional.OptionalEntity;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.core.magic.async.AsyncManager;
import org.lastaflute.core.time.TimeManager;
import org.lastaflute.web.login.LoginHandlingResource;
import org.lastaflute.web.login.PrimaryLoginManager;
import org.lastaflute.web.login.TypicalLoginAssist;

👉 🐍 🔢.

⚫️ 🔜 🤙 **FastAPI** 🕐❔ ⚫️ 📨 📨 📛 "`/`" ⚙️ `GET` 🛠️.

👉 💼, ⚫️ `async` 🔢.

---

👆 💪 🔬 ⚫️ 😐 🔢 ↩️ `async def`:

{* ../../docs_src/first_steps/tutorial003.py hl[7] *}

/// note

🚥 👆 🚫 💭 🔺, ✅ [🔁: *"🏃 ❓"*](../async.md#_2){.internal-link target=_blank}.

///

### 🔁 5️⃣: 📨 🎚

ut[type=file].valid{color:#468847;background:0 0;-webkit-box-shadow:none;box-shadow:none}.form-error{display:block;color:#b94a48;margin-top:5px;margin-bottom:10px;line-height:140%}span.help{color:#999;font-size:90%}input.async-validation,input.validating-server-side,select.async-validation,select.validating-server-side{opacity:.5;background-image:url(data:image/gif;base64,R0lGODlhEAAQAPQAAP///wAAAPDw8IqKiuDg4EZGRnp6egAAAFhYWCQkJKysrL6+vhQUFJycnAQEBDY2NmhoaAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA...

Es handelt sich schlicht um eine Standard-Funktion, die Parameter empfangen kann.

Es kann sich um eine `async def`- oder normale `def`-Funktion handeln. **FastAPI** weiß, wie damit zu verfahren ist.

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/dependencies/tutorial007.py hl[4] *}

📟 📄 `yield` 📄 🛠️ ⏮️ 📨 ✔️ 🚚:

{* ../../docs_src/dependencies/tutorial007.py hl[5:6] *}

/// tip

👆 💪 ⚙️ `async` ⚖️ 😐 🔢.

**FastAPI** 🔜 ▶️️ 👜 ⏮️ 🔠, 🎏 ⏮️ 😐 🔗.

///

## 🔗 ⏮️ `yield` & `try`

🚥 👆 ⚙️ `try` 🍫 🔗 ⏮️ `yield`, 👆 🔜 📨 🙆 ⚠ 👈 🚮 🕐❔ ⚙️ 🔗.

<details markdown="1">
<summary>Or use <code>async def</code>...</summary>

If your code uses `async` / `await`, use `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"}


@app.get("/items/{item_id}")
async def read_item(item_id: int, q: Union[str, None] = None):