# 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
```

, 🗄 👍 🚫 ⚙️ 👁 `Bucket` 🎚 💗 "<abbr title="A sequence of code being executed by the program, while at the same time, or at intervals, there can be others being executed too.">🧵</abbr>Ⓜ",, 👥 💪 🤚 🥡 🔗 &amp; 🚶‍♀️ ⚫️ 👆 🚙 🔢:

```Python hl_lines="49-53"
{!../../../docs_src/nosql_databases/tutorial001.py!}
```

## 🌃

* **Starlette**:
    * Tendrá el siguiente mejor desempeño, después de Uvicorn. De hecho, Starlette usa Uvicorn para correr. Por lo tanto, probablemente sólo pueda volverse "más lento" que Uvicorn al tener que ejecutar más código.

```

Quando você cria um gerenciador de contexto ou um gerenciador de contexto assíncrono como mencionado acima, o que ele faz é que, antes de entrar no bloco `with`, ele irá executar o código anterior ao `yield`, e depois de sair do bloco `with`, ele irá executar o código depois do `yield`.

No nosso exemplo de código acima, nós não usamos ele diretamente, mas nós passamos para o FastAPI para ele usá-lo.

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick")
        function ->> execute: execute function code
        execute ->> code: return the result
    end

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick", salutation="Mr.")
        function ->> execute: execute function code
        execute ->> code: return the result
    end

    rect rgba(0, 255, 255, .1)

    page = context.new_page()
    page.goto("http://localhost:8000/docs")
    page.get_by_text("GET/items/Read Items").click()
    page.get_by_role("button", name="Try it out").click()
    page.get_by_role("button", name="Execute").click()
    page.screenshot(
        path="docs/en/docs/img/tutorial/separate-openapi-schemas/image02.png"
    )

    # ---------------------
    context.close()
    browser.close()

* Any program, any code, **can only do things** when it is being **executed**. So, when there's a **process running**.
* The process can be **terminated** (or "killed") by you, or by the operating system. At that point, it stops running/being executed, and it can **no longer do things**.

Also, Couchbase recommends not using a single `Bucket` object in multiple "<abbr title="A sequence of code being executed by the program, while at the same time, or at intervals, there can be others being executed too.">thread</abbr>s", so, we can just get the bucket directly and pass it to our utility functions:

```Python hl_lines="49-53"
{!../../../docs_src/nosql_databases/tutorial001.py!}

* All of them will include the predefined `responses`.
* All these *path operations* will have the list of `dependencies` evaluated/executed before them.
    * If you also declare dependencies in a specific *path operation*, **they will be executed too**.

Ainsi, la section :

```Python
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

va s'exécuter.

---

Cela ne se produira pas si vous importez ce module (fichier).

Par exemple, si vous avez un autre fichier `importer.py` qui contient :

```Python
from myapp import app

# Code supplémentaire