It was one of the first extremely fast Python frameworks based on `asyncio`. It was made to be very similar to Flask.

/// note | Technical Details

It used <a href="https://github.com/MagicStack/uvloop" class="external-link" target="_blank">`uvloop`</a> instead of the default Python `asyncio` loop. That's what made it so fast.

        // Next command
        SMBUtil.writeInt4(0, buffer, bufferIndex + 20);
        // Message ID
        SMBUtil.writeInt8(1, buffer, bufferIndex + 24);
        // Reserved/Async ID
        SMBUtil.writeInt8(0, buffer, bufferIndex + 32);
        // Session ID
        SMBUtil.writeInt8(0, buffer, bufferIndex + 40);
        // Signature

	close       chan struct{}             // used for shutting down the splitter before end of stream
	readerWg    sync.WaitGroup            // used to keep track of async reader.
}

// queueItem is an item in the queue.
type queueItem struct {
	input []byte             // raw input sent to the worker
	dst   chan []jstream.KVS // result of block decode

高度なシナリオでは、「キャッシュされた」値を使うのではなく、同じリクエストの各ステップ（おそらく複数回）で依存関係を呼び出す必要があることがわかっている場合、`Depens`を使用する際に、`use_cache=False`というパラメータを設定することができます。

```Python hl_lines="1"
async def needy_dependency(fresh_value: str = Depends(get_value, use_cache=False)):
    return {"fresh_value": fresh_value}
```

## まとめ

ここで使われている派手な言葉は別にして、**依存性注入** システムは非常にシンプルです。

*path operation関数*と同じように見えるただの関数です。

```java
suggester.suggest()
    .setQuery("sea")
    .execute()
    .done(response -> {
        // Handle successful response
        response.getItems().forEach(item -> 
            System.out.println("Async suggestion: " + item.getText()[0])
        );
    })
    .error(throwable -> {
        // Handle error
        System.err.println("Error: " + throwable.getMessage());
    });
```

## Advanced Usage

            ChangeNotificationHandle handle = new ChangeNotificationHandle(directoryPath, leaseKey, directory);

            activeWatchers.put(directoryPath, handle);

            // Start async change notification
            startAsyncNotification(handle);

        } catch (Exception e) {
            log.error("Failed to start directory watching for: " + directoryPath, e);
        }
    }

		outBlock:           make(chan struct{}, outboundCap),
		LastPing:           time.Now().Unix(),
		BaseFlags:          c.baseFlags,
		clientPingInterval: c.clientPingInterval,
	}
	// Acknowledge Mux created.
	// Send async.
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		defer wg.Done()
		var ack message
		ack.Op = OpAckMux
		ack.Flags = m.BaseFlags
		ack.MuxID = m.ID
		m.send(ack)
		if debugPrint {

  html_url: https://github.com/liaogx/fastapi-tutorial
  stars: 1327
  owner_login: liaogx
  owner_html_url: https://github.com/liaogx
- name: fastapi-alembic-sqlmodel-async
  html_url: https://github.com/jonra1993/fastapi-alembic-sqlmodel-async
  stars: 1259
  owner_login: jonra1993
  owner_html_url: https://github.com/jonra1993
- name: fastapi-scaff
  html_url: https://github.com/atpuxiner/fastapi-scaff
  stars: 1255

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.

yield된 값은 *경로 작업* 및 다른 의존성들에 주입되는 값 입니다:

{* ../../docs_src/dependencies/tutorial007.py hl[4] *}

`yield`문 다음의 코드는 응답을 생성한 후 보내기 전에 실행됩니다:

{* ../../docs_src/dependencies/tutorial007.py hl[5:6] *}

/// tip | 팁

`async` 함수와 일반 함수 모두 사용할 수 있습니다.

**FastAPI**는 일반 의존성과 마찬가지로 각각의 함수를 올바르게 처리할 것입니다.

///

## `yield`와 `try`를 사용하는 의존성

`yield`를 사용하는 의존성에서 `try` 블록을 사용한다면, 의존성을 사용하는 도중 발생한 모든 예외를 받을 수 있습니다.