# Background Tasks - `BackgroundTasks`

You can declare a parameter in a *path operation function* or dependency function with the type `BackgroundTasks`, and then you can use it to schedule the execution of background tasks after the response is sent.

You can import it directly from `fastapi`:

```python
from fastapi import BackgroundTasks
```

## `BackgroundTasks` verwenden

Importieren Sie zunächst `BackgroundTasks` und definieren Sie einen Parameter in Ihrer *Pfadoperation-Funktion* mit der Typdeklaration `BackgroundTasks`:

```Python hl_lines="1  13"
{!../../docs_src/background_tasks/tutorial001.py!}
```

**FastAPI** erstellt für Sie das Objekt vom Typ `BackgroundTasks` und übergibt es als diesen Parameter.

from typing import Annotated

from fastapi import BackgroundTasks, Depends, FastAPI

app = FastAPI()


def write_log(message: str):
    with open("log.txt", mode="a") as log:
        log.write(message)


def get_query(background_tasks: BackgroundTasks, q: str | None = None):
    if q:
        message = f"found query: {q}\n"
        background_tasks.add_task(write_log, message)
    return q

## Usando `BackgroundTasks`

Primeiro, importe `BackgroundTasks` e defina um parâmetro em sua _função de operação de caminho_ com uma declaração de tipo de `BackgroundTasks`:

```Python hl_lines="1  13"
{!../../docs_src/background_tasks/tutorial001.py!}
```

O **FastAPI** criará o objeto do tipo `BackgroundTasks` para você e o passará como esse parâmetro.

## Using `BackgroundTasks`

First, import `BackgroundTasks` and define a parameter in your *path operation function* with a type declaration of `BackgroundTasks`:

{* ../../docs_src/background_tasks/tutorial001.py hl[1,13] *}

**FastAPI** will create the object of type `BackgroundTasks` for you and pass it as that parameter.

## Create a task function

from typing import Any, Callable

from starlette.background import BackgroundTasks as StarletteBackgroundTasks
from typing_extensions import Annotated, Doc, ParamSpec

P = ParamSpec("P")


class BackgroundTasks(StarletteBackgroundTasks):
    """
    A collection of background tasks that will be called after a response has been
    sent to the client.

    Read more about it in the

## Использование класса `BackgroundTasks`

Сначала импортируйте `BackgroundTasks`, потом добавьте в функцию параметр с типом `BackgroundTasks`:

```Python hl_lines="1  13"
{!../../docs_src/background_tasks/tutorial001.py!}
```

**FastAPI** создаст объект класса `BackgroundTasks` для вас и запишет его в параметр.

## Создание функции для фоновой задачи

## Utiliser `BackgroundTasks`

Pour commencer, importez `BackgroundTasks` et définissez un paramètre dans votre *fonction de chemin* avec `BackgroundTasks` comme type déclaré.

{* ../../docs_src/background_tasks/tutorial001.py hl[1,13] *}

**FastAPI** créera l'objet de type `BackgroundTasks` pour vous et le passera comme paramètre.

## Créer une fonction de tâche

    * 🖼, ➡️ 💬 👆 📨 📁 👈 🔜 🚶 🔘 🐌 🛠️, 👆 💪 📨 📨 "🚫" (🇺🇸🔍 2️⃣0️⃣2️⃣) & 🛠️ ⚫️ 🖥.

## ⚙️ `BackgroundTasks`

🥇, 🗄 `BackgroundTasks` & 🔬 🔢 👆 *➡ 🛠️ 🔢* ⏮️ 🆎 📄 `BackgroundTasks`:

```Python hl_lines="1  13"
{!../../docs_src/background_tasks/tutorial001.py!}
```

**FastAPI** 🔜 ✍ 🎚 🆎 `BackgroundTasks` 👆 & 🚶‍♀️ ⚫️ 👈 🔢.

## ✍ 📋 🔢

✍ 🔢 🏃 🖥 📋.

⚫️ 🐩 🔢 👈 💪 📨 🔢.

* 处理数据：
    * 例如，假设您收到的文件必须经过一个缓慢的过程，您可以返回一个"Accepted"(HTTP 202)响应并在后台处理它。

## 使用 `BackgroundTasks`

首先导入 `BackgroundTasks` 并在 *路径操作函数* 中使用类型声明 `BackgroundTasks` 定义一个参数：

```Python hl_lines="1  13"
{!../../docs_src/background_tasks/tutorial001.py!}
```

**FastAPI** 会创建一个 `BackgroundTasks` 类型的对象并作为该参数传入。

## 创建一个任务函数

创建要作为后台任务运行的函数。

它只是一个可以接收参数的标准函数。