As always, in FastAPI you can combine `def` and `async def` as needed.

    If you need a refresher about when to use which, check out the section _"In a hurry?"_ in the docs about [`async` and `await`](../async.md#in-a-hurry){.internal-link target=_blank}.

And then you also read how to handle [CORS with the `CORSMiddleware`](../tutorial/cors.md){.internal-link target=_blank}.

In this section we'll see how to use other middlewares.

## Adding ASGI middlewares { #adding-asgi-middlewares }

# 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.

      }
    };

    abstract void performAction(Random random, Iterable<? extends PrimitiveSink> sinks);

    private static final RandomHasherAction[] actions = values();

    static RandomHasherAction pickAtRandom(Random random) {
      return actions[random.nextInt(actions.length)];
    }
  }

  /**
   * Test that the hash function contains no funnels. A funnel is a situation where a set of input

# 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.

# Tutorial - User Guide { #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 { #run-the-code }

//     if v is nil, len(v) is zero.
//
// For some arguments, such as a string literal or a simple array expression, the
// result can be a constant. See the Go language specification's "Length and
// capacity" section for details.
func len(v Type) int

// The cap built-in function returns the capacity of v, according to its type:
//
//   - Array: the number of elements in v (same as len(v)).

      type: String?,
      data: String,
    )

    fun onRetryChange(timeMs: Long)
  }

  /**
   * Process the next event. This will result in a single call to [Callback.onEvent] *unless* the
   * data section was empty. Any number of calls to [Callback.onRetryChange] may occur while
   * processing an event.
   *
   * @return false when EOF is reached
   */
  @Throws(IOException::class)
  fun processNextEvent(): Boolean {

import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * A ScheduledExecutorService that executes all scheduled actions immediately in the calling thread.
 *
 * <p>See {@link TestingExecutors#sameThreadScheduledExecutor()} for a full list of constraints.
 *
 * @author John Sirois
 * @author Zach van Schouwen
 */
@GwtIncompatible

import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * A ScheduledExecutorService that executes all scheduled actions immediately in the calling thread.
 *
 * <p>See {@link TestingExecutors#sameThreadScheduledExecutor()} for a full list of constraints.
 *
 * @author John Sirois
 * @author Zach van Schouwen
 */
@GwtIncompatible