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

## A Custom `PNGStreamingResponse` { #a-custom-pngstreamingresponse }

In the examples above, the data bytes were streamed, but the response didn't have a `Content-Type` header, so the client didn't know what type of data it was receiving.

      TYPE_DATA -> readData(handler, length, flags, streamId)
      TYPE_HEADERS -> readHeaders(handler, length, flags, streamId)
      TYPE_PRIORITY -> readPriority(handler, length, flags, streamId)
      TYPE_RST_STREAM -> readRstStream(handler, length, flags, streamId)
      TYPE_SETTINGS -> readSettings(handler, length, flags, streamId)
      TYPE_PUSH_PROMISE -> readPushPromise(handler, length, flags, streamId)

# Daten streamen { #stream-data }

Wenn Sie Daten streamen möchten, die als JSON strukturiert werden können, sollten Sie [JSON Lines streamen](../tutorial/stream-json-lines.md).

Wenn Sie jedoch **reine Binärdaten** oder Strings streamen möchten, so können Sie es machen.

/// info | Info

Hinzugefügt in FastAPI 0.134.0.

///

## Anwendungsfälle { #use-cases }

/// tip | Tipp

Wenn Sie Binärdaten streamen wollen, z. B. Video oder Audio, sehen Sie im fortgeschrittenen Handbuch nach: [Daten streamen](../advanced/stream-data.md).

///

## SSE mit FastAPI streamen { #stream-sse-with-fastapi }

Um SSE mit FastAPI zu streamen, verwenden Sie `yield` in Ihrer *Pfadoperation-Funktion* und setzen Sie `response_class=EventSourceResponse`.

/// tip | Tipp

Wenn Sie Binärdaten streamen möchten, zum Beispiel Video oder Audio, sehen Sie sich den erweiterten Leitfaden an: [Daten streamen](../advanced/stream-data.md).

///

## JSON Lines mit FastAPI streamen { #stream-json-lines-with-fastapi }

     * Even if empty string, treated as empty plainly. So "IF pmb != null" is false if empty.
     * @param level The parameter value of level. (NotNull)
     */
    public void setLevel(String level) {
        registerVariable("level", level);
    }

    /**
     * Set the value of hostname, used in parameter comment. <br>
     * Even if empty string, treated as empty plainly. So "IF pmb != null" is false if empty.

  }

  /**
   * Returns the value of the given {@code int} as a {@code long}, when treated as unsigned.
   *
   * <p><b>Java 8+ users:</b> use {@link Integer#toUnsignedLong(int)} instead.
   */
  public static long toLong(int value) {
    return value & INT_MASK;
  }

  /**
   * Returns the {@code int} value that, when treated as unsigned, is equal to {@code value}, if
   * possible.
   *

    return Byte.toUnsignedInt(value);
  }

  /**
   * Returns the {@code byte} value that, when treated as unsigned, is equal to {@code value}, if
   * possible.
   *
   * @param value a value between 0 and 255 inclusive
   * @return the {@code byte} value that, when treated as unsigned, equals {@code value}
   * @throws IllegalArgumentException if {@code value} is negative or greater than 255
   */

    * Pydantic also allows representing it as a "ISO 8601 time diff encoding", [see the docs for more info](https://docs.pydantic.dev/latest/concepts/serialization/#custom-serializers).
* `frozenset`:
    * In requests and responses, treated the same as a `set`:
        * In requests, a list will be read, eliminating duplicates and converting it to a `set`.
        * In responses, the `set` will be converted to a `list`.

///

/// tip | Tipp

Anstatt eine `StreamingResponse` direkt zurückzugeben, sollten Sie wahrscheinlich dem Stil in [Daten streamen](./stream-data.md) folgen. Das ist wesentlich bequemer und behandelt den Abbruch im Hintergrund für Sie.

Wenn Sie JSON Lines streamen, folgen Sie dem Tutorial [JSON Lines streamen](../tutorial/stream-json-lines.md).

///

### `FileResponse` { #fileresponse }