To install the current release, which includes support for
[CUDA-enabled GPU cards](https://www.tensorflow.org/install/gpu) *(Ubuntu and
Windows)*:

```
$ pip install tensorflow
```

Other devices (DirectX and MacOS-metal) are supported using
[Device plugins](https://www.tensorflow.org/install/gpu_plugins#available_devices).

A smaller CPU-only package is also available:

```
$ pip install tensorflow-cpu
```

	"os"
	"syscall"

	"github.com/ncw/directio"
	"golang.org/x/sys/unix"
)

// ODirectPlatform indicates if the platform supports O_DIRECT
const ODirectPlatform = true

// OpenFileDirectIO - bypass kernel cache.
func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error) {
	return directio.OpenFile(filePath, flag, perm)
}

// DisableDirectIO - disables directio mode.

// ODirectPlatform indicates if the platform supports O_DIRECT
const ODirectPlatform = false

// OpenBSD, Windows, and illumos do not support O_DIRECT.
// On Windows there is no documentation on disabling O_DIRECT.
// For these systems we do not attempt to build the 'directio' dependency since
// the O_DIRECT symbol may not be exposed resulting in a failed build.
//
//
// On illumos an explicit O_DIRECT flag is not necessary for two primary

import (
	"os"

	"github.com/ncw/directio"
	"golang.org/x/sys/unix"
)

// ODirectPlatform indicates if the platform supports O_DIRECT
const ODirectPlatform = true

// OpenFileDirectIO - bypass kernel cache.
func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error) {
	return directio.OpenFile(filePath, flag, perm)
}

// DisableDirectIO - disables directio mode.

```Python hl_lines="6-7  21-22"
{!../../../docs_src/response_directly/tutorial001.py!}
```

!!! note "Technische Details"
    Sie können auch `from starlette.responses import JSONResponse` verwenden.

    **FastAPI** bietet dieselben `starlette.responses` auch via `fastapi.responses` an, als Annehmlichkeit für Sie, den Entwickler. Die meisten verfügbaren Responses kommen aber direkt von Starlette.

## Eine benutzerdefinierte `Response` zurückgeben

## Das `Request`-Objekt direkt verwenden

Angenommen, Sie möchten auf die IP-Adresse/den Host des Clients in Ihrer *Pfadoperation-Funktion* zugreifen.

Dazu müssen Sie direkt auf den Request zugreifen.

```Python hl_lines="1  7-8"
{!../../../docs_src/using_request_directly/tutorial001.py!}
```

Pour ces cas, vous pouvez spécifier un appel à `jsonable_encoder` pour convertir vos données avant de les passer à une réponse :

```Python hl_lines="6-7  21-22"
{!../../../docs_src/response_directly/tutorial001.py!}
```

!!! note "Détails techniques"
    Vous pouvez aussi utiliser `from starlette.responses import JSONResponse`.

But you can return a `JSONResponse` directly from your *path operations*.

It might be useful, for example, to return custom headers or cookies.

## Return a `Response`

In fact, you can return any `Response` or any sub-class of it.

!!! tip
    `JSONResponse` itself is a sub-class of `Response`.

And when you return a `Response`, **FastAPI** will pass it directly.

📚 💼, 👆 💪 ⚙️ `jsonable_encoder` 🗜 👆 📊 ⏭ 🚶‍♀️ ⚫️ 📨:

```Python hl_lines="6-7  21-22"
{!../../../docs_src/response_directly/tutorial001.py!}
```

!!! note "📡 ℹ"
    👆 💪 ⚙️ `from starlette.responses import JSONResponse`.

    **FastAPI** 🚚 🎏 `starlette.responses` `fastapi.responses` 🏪 👆, 👩‍💻. ✋️ 🌅 💪 📨 👟 🔗 ⚪️➡️ 💃.

But there are specific cases where it's useful to get the `Request` object.

## Use the `Request` object directly

Let's imagine you want to get the client's IP address/host inside of your *path operation function*.

For that you need to access the request directly.

```Python hl_lines="1  7-8"
{!../../../docs_src/using_request_directly/tutorial001.py!}
```