### Étape 1 : import `FastAPI`

{* ../../docs_src/first_steps/tutorial001.py hl[1] *}

`FastAPI` est une classe Python qui fournit toutes les fonctionnalités nécessaires au lancement de votre API.

/// note | Détails techniques

`FastAPI` est une classe héritant directement de `Starlette`.

C'était l'un des premiers frameworks Python extrêmement rapides basés sur `asyncio`. Il a été conçu pour être très similaire à Flask.

/// note | Détails techniques

Il utilisait <a href="https://github.com/MagicStack/uvloop" class="external-link" target="_blank">`uvloop`</a> au lieu du système par défaut de Python `asyncio`. C'est ce qui l'a rendu si rapide.

     * <p>
     * This method checks if the resolved absolute path starts with the allowed base directory,
     * preventing access to files outside the intended directory through path traversal
     * techniques like "../../../etc/passwd".
     * </p>
     * <p>
     * Example usage:
     * </p>
     * <pre>
     * Path baseDir = Paths.get("/var/app/data");
     * Path userPath = Paths.get(userInput);

But it is way more complex than that.

/// tip

If you are in a hurry or don't care, continue with the next sections for step by step instructions to set everything up with different techniques.

///

To **learn the basics of HTTPS**, from a consumer perspective, check <a href="https://howhttps.works/" class="external-link" target="_blank">https://howhttps.works/</a>.

	tx = db.getInstance()
	tx.Statement.Model = value
	return
}

// Clauses Add clauses
//
// This supports both standard clauses (clause.OrderBy, clause.Limit, clause.Where) and more
// advanced techniques like specifying lock strength and optimizer hints. See the
// [docs] for more depth.
//
//	// add a simple limit clause
//	db.Clauses(clause.Limit{Limit: 1}).Find(&User{})

 * ranking scores to provide more comprehensive and accurate search results.
 *
 * The processor maintains a pool of searchers and an executor service for concurrent operations.
 * It implements rank fusion techniques to combine results from different search engines
 * and provides a unified search interface.
 */
public class RankFusionProcessor implements AutoCloseable {

* Sécurité et authentification, y compris la prise en charge de **OAuth2** avec les **<abbr title="en anglais : JWT tokens">jetons <abbr title="JSON Web Tokens">JWT</abbr></abbr>** et l'authentification **HTTP Basic**.
* Des techniques plus avancées (mais tout aussi faciles) pour déclarer les **modèles <abbr title="JavaScript Object Notation">JSON</abbr> profondément imbriqués** (grâce à Pydantic).

* Security and authentication, including support for **OAuth2** with **JWT tokens** and **HTTP Basic** auth.
* More advanced (but equally easy) techniques for declaring **deeply nested JSON models** (thanks to Pydantic).
* **GraphQL** integration with <a href="https://strawberry.rocks" class="external-link" target="_blank">Strawberry</a> and other libraries.

* Security and authentication, including support for **OAuth2** with **JWT tokens** and **HTTP Basic** auth.
* More advanced (but equally easy) techniques for declaring **deeply nested JSON models** (thanks to Pydantic).
* **GraphQL** integration with <a href="https://strawberry.rocks" class="external-link" target="_blank">Strawberry</a> and other libraries.

You might want to have some predefined responses that apply to many *path operations*, but you want to combine them with custom responses needed by each *path operation*.

For those cases, you can use the Python technique of "unpacking" a `dict` with `**dict_to_unpack`:

```Python
old_dict = {
    "old key": "old value",
    "second old key": "second old value",
}
new_dict = {**old_dict, "new key": "new value"}
```