binary_image = base64.b64decode(image_base64)


def read_image() -> BytesIO:
    return BytesIO(binary_image)


app = FastAPI()


class PNGStreamingResponse(StreamingResponse):
    media_type = "image/png"


@app.get("/image/stream", response_class=PNGStreamingResponse)
async def stream_image() -> AsyncIterable[bytes]:
    with read_image() as image_file:
        for chunk in image_file:

Esto también significa que con `StreamingResponse` tienes la libertad y la responsabilidad de producir y codificar los bytes de datos exactamente como necesites enviarlos, independientemente de las anotaciones de tipos. 🤓

### Transmitir bytes { #stream-bytes }

Uno de los casos de uso principales sería transmitir `bytes` en lugar de strings; por supuesto puedes hacerlo.

{* ../../docs_src/stream_data/tutorial001_py310.py ln[44:47] hl[47] *}

### Bytes Akışı { #stream-bytes }

Başlıca kullanım senaryolarından biri string yerine `bytes` akıtmaktır; elbette bunu yapabilirsiniz.

{* ../../docs_src/stream_data/tutorial001_py310.py ln[44:47] hl[47] *}

## Özel bir `PNGStreamingResponse` { #a-custom-pngstreamingresponse }

Isso também significa que, com `StreamingResponse`, você tem a liberdade e a responsabilidade de produzir e codificar os bytes exatamente como precisam ser enviados, independentemente das anotações de tipo. 🤓

### Transmitir bytes { #stream-bytes }

Um dos principais casos de uso é transmitir `bytes` em vez de strings; você pode fazer isso sem problemas.

{* ../../docs_src/stream_data/tutorial001_py310.py ln[44:47] hl[47] *}

### Bytes streamen { #stream-bytes }

Einer der Hauptanwendungsfälle wäre, `bytes` statt Strings zu streamen, das können Sie selbstverständlich tun.

{* ../../docs_src/stream_data/tutorial001_py310.py ln[44:47] hl[47] *}

This also means that with `StreamingResponse` you have the **freedom** and **responsibility** to produce and encode the data bytes exactly as you need them to be sent, independent of the type annotations. 🤓

### Stream Bytes { #stream-bytes }

One of the main use cases would be to stream `bytes` instead of strings, you can of course do it.

{* ../../docs_src/stream_data/tutorial001_py310.py ln[44:47] hl[47] *}

### Потоковая передача байтов { #stream-bytes }

Один из основных сценариев — стримить `bytes` вместо строк, и, конечно, это можно сделать.

{* ../../docs_src/stream_data/tutorial001_py310.py ln[44:47] hl[47] *}

## Пользовательский `PNGStreamingResponse` { #a-custom-pngstreamingresponse }

{* ../../docs_src/stream_data/tutorial001_py310.py ln[32:35] hl[33] *}

這也意味著使用 `StreamingResponse` 時，你擁有自由與責任，需依需求自行產生並編碼要傳送的位元組資料，與型別註解無關。 🤓

### 串流位元組 { #stream-bytes }

一個主要用例是串流 `bytes` 而非字串，當然可以這麼做。

{* ../../docs_src/stream_data/tutorial001_py310.py ln[44:47] hl[47] *}

## 自訂 `PNGStreamingResponse` { #a-custom-pngstreamingresponse }

### Diffuser des bytes { #stream-bytes }

L'un des principaux cas d'usage consiste à diffuser des `bytes` au lieu de chaînes ; vous pouvez bien sûr le faire.

{* ../../docs_src/stream_data/tutorial001_py310.py ln[44:47] hl[47] *}

### 模拟文件 { #simulate-a-file }

在这个示例中，我们用 `io.BytesIO` 模拟了一个文件，它是只驻留在内存中的类文件对象，但提供相同的接口。

例如，我们可以像对文件那样迭代它来消费其内容。

{* ../../docs_src/stream_data/tutorial002_py310.py ln[1:27] hl[3,12:13,25] *}

/// note | 技术细节

另外两个变量 `image_base64` 和 `binary_image` 表示一张图像，先用 Base64 编码，再转换为 bytes，最后传给 `io.BytesIO`。

只是为了让它们能和示例放在同一个文件里，便于你直接复制运行。🥚

///