## Recap

You have been reading here some of the main concepts that you would probably need to keep in mind when deciding how to deploy your application:

* Security - HTTPS
* Running on startup
* Restarts

    しかし例外ハンドラで処理されない例外を発生させた場合は、依存関係の終了コードで処理されます。

## コンテキストマネージャ

### 「コンテキストマネージャ」とは

「コンテキストマネージャ」とは、`with`文の中で使用できるPythonオブジェクトのことです。

例えば、<a href="https://docs.python.org/3/tutorial/inputoutput.html#reading-and-writing-files" class="external-link" target="_blank">ファイルを読み込むには`with`を使用することができます</a>:

```Python
with open("./somefile.txt") as f:
    contents = f.read()
    print(contents)
```

		format.Erasure.Sets[i] = make([]string, setLen)
		for j := 0; j < setLen; j++ {
			format.Erasure.Sets[i][j] = mustGetUUID()
		}
	}
	return format
}

// Returns format Erasure version after reading `format.json`, returns
// successfully the version only if the backend is Erasure.
func formatGetBackendErasureVersion(b []byte) (string, error) {
	meta := &formatMetaV1{}
	if err := json.Unmarshal(b, meta); err != nil {

			case ObjectNotFound, InsufficientReadQuorum:
				retryWait()
				continue
			}
			// Allow one fast retry for other errors.
			if retries > 0 {
				return entries, fmt.Errorf("reading first part metadata: %v", err)
			}
			retryWait()
			continue
		}

		partN, err := o.findFirstPart(fi)
		switch {
		case err == nil:
		case errors.Is(err, io.ErrUnexpectedEOF):

		}
	}()

	buf := NewBuffer(make([]byte, 1))
	const maxInt = int(^uint(0) >> 1)
	buf.Grow(maxInt)
}

// Was a bug: used to give EOF reading empty slice at EOF.
func TestReadEmptyAtEOF(t *testing.T) {
	b := new(Buffer)
	slice := make([]byte, 0)
	n, err := b.Read(slice)
	if err != nil {
		t.Errorf("read error: %v", err)
	}
	if n != 0 {

  }

  private fun failConnection(e: IOException?) {
    close(ErrorCode.PROTOCOL_ERROR, ErrorCode.PROTOCOL_ERROR, e)
  }

  /**
   * Sends any initial frames and starts reading frames from the remote peer. This should be called
   * after [Builder.build] for all new connections.
   *
   * @param sendConnectionPreface true to send connection preface frames. This should always be true

    return {};
  }
  const auto& fdef_lib = gdef.library();
  if (fdef_lib.gradient_size() > 0) {
    status->status = tensorflow::errors::Internal(
        "GradientDef is not supported in reading Dataset related functions: ",
        text_proto);
    return {};
  }
  std::vector<UniqueFuncPtr> ret;
  for (const FunctionDef& fdef : fdef_lib.function()) {
    // Make a copy so that we can mutate it.

Aún así, en ambas situaciones, es probable que **FastAPI** sea [aún más rápido](index.md#rendimiento){.Internal-link target=_blank} que (o al menos comparable) a tu framework anterior.

That's why in this example we have to declare it in the `response_model` parameter.

...but continue reading below to see how to overcome that.

## Return Type and Data Filtering

Let's continue from the previous example. We wanted to **annotate the function with one type** but return something that includes **more data**.

### <a href="https://webargs.readthedocs.io/en/latest/" class="external-link" target="_blank">Webargs</a>

Another big feature required by APIs is <abbr title="reading and converting to Python data">parsing</abbr> data from incoming requests.

Webargs is a tool that was made to provide that on top of several frameworks, including Flask.