## Kontextmanager { #context-managers }

### Was sind „Kontextmanager“ { #what-are-context-managers }

„Kontextmanager“ (Englisch „Context Manager“) sind bestimmte Python-Objekte, die Sie in einer `with`-Anweisung verwenden können.

## Gerenciadores de contexto { #context-managers }

### O que são "Gerenciadores de Contexto" { #what-are-context-managers }

"Gerenciadores de Contexto" são qualquer um dos objetos Python que podem ser utilizados com a declaração `with`.

# yieldを持つ依存関係

FastAPIは、いくつかの<abbr title='時々"exit"、"cleanup"、"teardown"、"close"、"context managers"、 ...のように呼ばれる'>終了後の追加のステップ</abbr>を行う依存関係をサポートしています。

これを行うには、`return`の代わりに`yield`を使い、その後に追加のステップを書きます。

/// tip | 豆知識

`yield`は必ず一度だけ使用するようにしてください。

///

/// info | 情報

これを動作させるには、**Python 3.7** 以上を使用するか、**Python 3.6** では"backports"をインストールする必要があります:

```
pip install async-exit-stack async-generator
```

      )
    factory.init(null as KeyStore?)
    val trustManagers = factory.trustManagers!!
    check(trustManagers.size == 1 && trustManagers[0] is X509TrustManager) {
      "Unexpected default trust managers: ${trustManagers.contentToString()}"
    }
    return trustManagers[0] as X509TrustManager
  }

  override fun trustManager(sslSocketFactory: SSLSocketFactory): X509TrustManager =
    throw UnsupportedOperationException(

        provider,
      )
    factory.init(null as KeyStore?)
    val trustManagers = factory.trustManagers!!
    check(trustManagers.size == 1 && trustManagers[0] is X509TrustManager) {
      "Unexpected default trust managers: ${trustManagers.contentToString()}"
    }
    return trustManagers[0] as X509TrustManager
  }

  override fun trustManager(sslSocketFactory: SSLSocketFactory): X509TrustManager =
    throw UnsupportedOperationException(

        .apply {
          init(null as KeyStore?)
        }.trustManagers!!
    check(trustManagers.size == 1 && trustManagers[0] is X509TrustManager) {
      "Unexpected default trust managers: ${trustManagers.contentToString()}"
    }
    val x509TrustManager = trustManagers[0] as X509TrustManager
    // Disabled because OkHttp will run anyway

    TrustManager[] trustManagers = trustManagerFactory.getTrustManagers();
    if (trustManagers.length != 1 || !(trustManagers[0] instanceof X509TrustManager)) {
      throw new IllegalStateException("Unexpected default trust managers:"
          + Arrays.toString(trustManagers));
    }
    return (X509TrustManager) trustManagers[0];
  }

  private String[] javaNames(List<CipherSuite> cipherSuites) {

# 使用yield的依赖项

FastAPI支持在完成后执行一些<abbr title='有时也被称为"退出"("exit")，"清理"("cleanup")，"拆卸"("teardown")，"关闭"("close")，"上下文管理器"("context managers")。 ...'>额外步骤</abbr>的依赖项.

为此，你需要使用 `yield` 而不是 `return`，然后再编写这些额外的步骤（代码）。

/// tip | 提示

确保在每个依赖中只使用一次 `yield`。

///

/// note | 技术细节

任何一个可以与以下内容一起使用的函数：

    check(trustManagers.size == 1 && trustManagers[0] is X509TrustManager) {
      "Unexpected default trust managers: ${trustManagers.contentToString()}"
    }
    return trustManagers[0] as X509TrustManager
  }

  open fun trustManager(sslSocketFactory: SSLSocketFactory): X509TrustManager? {
    return try {
      // Attempt to get the trust manager from an OpenJDK socket factory. We attempt this on all

원하는 의존성을 원하는 대로 조합할 수 있습니다.

**FastAPI**는 모든 것이 올바른 순서로 실행되도록 보장합니다.

/// note | 기술 세부사항

파이썬의 <a href=“https://docs.python.org/3/library/contextlib.html” class=“external-link” target=“_blank”>Context Managers</a> 덕분에 이 기능이 작동합니다.

**FastAPI**는 이를 내부적으로 컨텍스트 관리자를 사용하여 구현합니다.

///

## `yield`와 `HTTPException`를 사용하는 의존성

`yield`와 `try` 블록이 있는 의존성을 사용하여 예외를 처리할 수 있다는 것을 알게 되었습니다.