* example is when a server has just booted, and it is mostly busy with getting itself up to
   * speed).
   *
   * To deal with such scenarios, we add an extra dimension, that of "past underutilization",
   * modeled by "storedPermits" variable. This variable is zero when there is no underutilization,
   * and it can grow up to maxStoredPermits, for sufficiently large underutilization. So, the

///

#### Data with values for fields with defaults { #data-with-values-for-fields-with-defaults }

But if your data has values for the model's fields with default values, like the item with ID `bar`:

```Python hl_lines="3  5"
{
    "name": "Bar",
    "description": "The bartenders",
    "price": 62,
    "tax": 20.2
}
```

Kullanımı çok kolay ve sezgisel, kolaylıkla genişletilebilecek ve modüler bileşenlere sahip olacak şekilde tasarlandı.

Sahip olduğu bir kaç özellik:

* Cidden etkileyici bir performans.
* WebSocket desteği.
* İşlem-içi arka plan görevleri.
* Başlatma ve kapatma olayları.

### Concurrence + Parallélisme : Web + Machine Learning

Avec **FastAPI** vous pouvez bénéficier de la concurrence qui est très courante en développement web (c'est l'attrait principal de NodeJS).

Il ne peut pas très bien gérer les modèles imbriqués. Ainsi, si le corps JSON de la requête est un objet JSON comportant des champs internes qui sont à leur tour des objets JSON imbriqués, il ne peut pas être correctement documenté et validé.

			//   extra care when printing them - ignore since it is not
			//   going to change w/o a language change.
			// - Internal and vendored packages do not contribute to our
			//   API surface. (If we are running within the "std" module,
			//   vendored dependencies appear as themselves instead of
			//   their "vendor/" standard-library copies.)
			// - 'go list std' does not include commands, which cannot be
			//   imported anyway.

<div class="termy">

```console
$ cd ~/code/prisoner-of-azkaban

$ python main.py

// 匯入 sirius 錯誤，未安裝 😱
Traceback (most recent call last):
    File "main.py", line 1, in <module>
        import sirius
```

</div>

但如果你停用虛擬環境並啟用 `prisoner-of-askaban` 的新虛擬環境，那麼當你執行 `python` 時，它會使用 `prisoner-of-askaban` 中虛擬環境的 Python。

<div class="termy">

```console

<div class="termy">

```console
$ cd ~/code/prisoner-of-azkaban

$ python main.py

// 导入 sirius 报错，它没有安装 😱
Traceback (most recent call last):
    File "main.py", line 1, in <module>
        import sirius
```

</div>

但是如果你停用虚拟环境并激活 `prisoner-of-askaban` 的新虚拟环境，那么当你运行 `python` 时，它会使用 `prisoner-of-askaban` 中的虚拟环境中的 Python。

<div class="termy">

```console

It is very simple and intuitive. It's designed to be easily extensible, and have modular components.

It has:

* Seriously impressive performance.
* WebSocket support.
* In-process background tasks.
* Startup and shutdown events.
* Test client built on HTTPX.

<div class="termy">

```console
$ cd ~/code/prisoner-of-azkaban

$ python main.py

// sirius를 임포트하는 데 실패했습니다. 설치되어 있지 않아요 😱
Traceback (most recent call last):
    File "main.py", line 1, in <module>
        import sirius
```

</div>

하지만 `마법사의 돌(philosophers-stone)`의 가상 환경을 비활성화한 다음, `아즈카반의 죄수(prisoner-of-azkaban)` 프로젝트의 가상 환경을 활성화하면, 이제 `python` 명령어는 `아즈카반의 죄수(prisoner-of-azkaban)` 가상 환경의 Python을 사용하게 됩니다.