For example, if you want to read or manipulate the request body before it is processed by your application.

/// danger

This is an "advanced" feature.

If you are just starting with **FastAPI** you might want to skip this section.

///

## Use cases

Some use cases include:

* Converting non-JSON request bodies to JSON (e.g. <a href="https://msgpack.org/index.html" class="external-link" target="_blank">`msgpack`</a>).

# Tutoriel - Guide utilisateur - Introduction

Ce tutoriel vous montre comment utiliser **FastAPI** avec la plupart de ses fonctionnalités, étape par étape.

Chaque section s'appuie progressivement sur les précédentes, mais elle est structurée de manière à séparer les sujets, afin que vous puissiez aller directement à l'un d'entre eux pour résoudre vos besoins spécifiques en matière d'API.

Il est également conçu pour fonctionner comme une référence future.

  }

  /*
   * We co-opt some URI resolution tests for our purposes.
   * Some of the tests have queries and anchors that are a little silly here.
   */

  /** http://gbiv.com/protocols/uri/rfc/rfc2396.html#rfc.section.C.1 */
  public void testRfc2396Normal() {
    assertEquals("/a/b/c/g", simplifyPath("/a/b/c/g"));
    assertEquals("/a/b/c/g", simplifyPath("/a/b/c/./g"));
    assertEquals("/a/b/c/g", simplifyPath("/a/b/c/g/"));

  }

  /*
   * We co-opt some URI resolution tests for our purposes.
   * Some of the tests have queries and anchors that are a little silly here.
   */

  /** http://gbiv.com/protocols/uri/rfc/rfc2396.html#rfc.section.C.1 */
  public void testRfc2396Normal() {
    assertEquals("/a/b/c/g", simplifyPath("/a/b/c/g"));
    assertEquals("/a/b/c/g", simplifyPath("/a/b/c/./g"));
    assertEquals("/a/b/c/g", simplifyPath("/a/b/c/g/"));

    private const val TE = "te"
    private const val ENCODING = "encoding"
    private const val UPGRADE = "upgrade"

    /** See http://tools.ietf.org/html/draft-ietf-httpbis-http2-09#section-8.1.3. */
    private val HTTP_2_SKIPPED_REQUEST_HEADERS =
      immutableListOf(
        CONNECTION,
        HOST,
        KEEP_ALIVE,
        PROXY_CONNECTION,
        TE,
        TRANSFER_ENCODING,

 *  * If `server_max_window_bits` is less than 15, OkHttp will waste memory on an oversized buffer.
 *
 * See [RFC 7692, 7.1][rfc_7692] for details on negotiation process.
 *
 * [rfc_7692]: https://tools.ietf.org/html/rfc7692#section-7.1
 */
@IgnoreJRERequirement // As of AGP 3.4.1, D8 desugars API 24 hashCode methods.
data class WebSocketExtensions(
  /** True if the agreed upon extensions includes the permessage-deflate extension. */

# Tutorial - User Guide

This tutorial shows you how to use **FastAPI** with most of its features, step by step.

Each section gradually builds on the previous ones, but it's structured to separate topics, so that you can go directly to any specific one to solve your specific API needs.

It is also built to work as a future reference so you can come back and see exactly what you need.

## Run the code

# 벤치마크

독립적인 TechEmpower 벤치마크에 따르면 **FastAPI** 애플리케이션이 Uvicorn을 사용하여 <a href="https://www.techempower.com/benchmarks/#section=test&runid=7464e520-0dc2-473d-bd34-dbdfd7e85911&hw=ph&test=query&l=zijzen-7" class="external-link" target="_blank">가장 빠른 Python 프레임워크 중 하나</a>로 실행되며, Starlette와 Uvicorn 자체(내부적으로 FastAPI가 사용하는 도구)보다 조금 아래에 위치합니다.

그러나 벤치마크와 비교를 확인할 때 다음 사항을 염두에 두어야 합니다.

## 벤치마크와 속도

벤치마크를 확인할 때, 일반적으로 여러 가지 유형의 도구가 동등한 것으로 비교되는 것을 볼 수 있습니다.

```html
Item ID: 42
```

### Template `url_for` Arguments

You can also use `url_for()` inside of the template, it takes as arguments the same arguments that would be used by your *path operation function*.

So, the section with:

{% raw %}

```jinja
<a href="{{ url_for('read_item', id=id) }}">
```

{% endraw %}

# Замеры производительности

Независимые тесты производительности приложений от TechEmpower показывают, что **FastAPI** под управлением Uvicorn <a href="https://www.techempower.com/benchmarks/#section=test&runid=7464e520-0dc2-473d-bd34-dbdfd7e85911&hw=ph&test=query&l=zijzen-7" class="external-link" target="_blank">один из самых быстрых Python-фреймворков</a> и уступает только Starlette и Uvicorn (которые используются в FastAPI). (*)