# Concurrence et les mots-clés async et await

Cette page vise à fournir des détails sur la syntaxe `async def` pour les *fonctions de chemins* et quelques rappels sur le code asynchrone, la concurrence et le parallélisme.

## Vous êtes pressés ?

<abbr title="'too long; didn't read' en anglais, ou 'trop long ; j'ai pas lu'"><strong>TL;DR :</strong></abbr>

Si vous utilisez des bibliothèques tierces qui nécessitent d'être appelées avec `await`, telles que :

Inklusive externer Bibliotheken, die auf Pydantic basieren, wie <abbr title="Object-Relational Mapper (Abbildung von Objekten auf relationale Strukturen)">ORM</abbr>s, <abbr title="Object-Document Mapper (Abbildung von Objekten auf nicht-relationale Strukturen)">ODM</abbr>s für Datenbanken.

**FastAPI**は<a href="https://docs.pydantic.dev/" class="external-link" target="_blank"><strong>Pydantic </strong></a>と完全に互換性があります（そしてベースになっています）。したがって、追加のPydanticコードがあれば、それも機能します。

データベースのために<abbr title = "Object-Relational Mapper">ORM</abbr>sや、<abbr title = "Object-Document Mapper">ODM</abbr>sなどの、Pydanticに基づく外部ライブラリを備えています。

これは、すべてが自動的に検証されるため、多くの場合、リクエストから取得したオブジェクトを**データベースに直接**渡すことができるということを意味しています。

同じことがその逆にも当てはまり、多くの場合、データベースから取得したオブジェクトを**クライアントに直接**渡すことができます。

    * The information about the **specific domain** requested goes in the **HTTP data**.
* The **HTTPS certificates** "certify" a **certain domain**, but the protocol and encryption happen at the TCP level, **before knowing** which domain is being dealt with.
* **By default**, that would mean that you can only have **one HTTPS certificate per IP address**.

    So, behind the scenes, it will actually work as if everything was the same single app.

!!! check
    You don't have to worry about performance when including routers.

    This will take microseconds and will only happen at startup.

    So it won't affect performance. ⚡

### Include an `APIRouter` with a custom `prefix`, `tags`, `responses`, and `dependencies`

```Python
    first_name="john", last_name="doe"
```

It's a different thing.

We are using colons (`:`), not equals (`=`).

And adding type hints normally doesn't change what happens from what would happen without them.

But now, imagine you are again in the middle of creating that function, but with type hints.

At the same point, you try to trigger the autocomplete with `Ctrl+Space` and you see:

```Python
async def do_something():
    try:
        yield something
    finally:
        some_cleanup()
```

...that way the `finally` block is run regardless of any exception that might happen.

### Features

* The same PR [#4575](https://github.com/tiangolo/fastapi/pull/4575) from above also fixes the `contextvars` context for the code before and after `yield`. This was the main objective of that PR.

Including external libraries also based on Pydantic, as <abbr title="Object-Relational Mapper">ORM</abbr>s, <abbr title="Object-Document Mapper">ODM</abbr>s for databases.

This also means that in many cases you can pass the same object you get from a request **directly to the database**, as everything is validated automatically.

Incluindo bibliotecas externas também baseadas no Pydantic, como <abbr title="Object-Relational Mapper">ORM</abbr>s e <abbr title="Object-Document Mapper">ODM</abbr>s para bancos de dados.

✅ 🔢 🗃 ⚓️ 🔛 Pydantic, <abbr title="Object-Relational Mapper">🐜</abbr>Ⓜ, <abbr title="Object-Document Mapper">🏭</abbr>Ⓜ 💽.

👉 ⛓ 👈 📚 💼 👆 💪 🚶‍♀️ 🎏 🎚 👆 🤚 ⚪️➡️ 📨 **🔗 💽**, 🌐 ✔ 🔁.

🎏 ✔ 🎏 🌌 🤭, 📚 💼 👆 💪 🚶‍♀️ 🎚 👆 🤚 ⚪️➡️ 💽 **🔗 👩‍💻**.