## OpenAPI Client Generators

There are many tools to generate clients from **OpenAPI**.

A common tool is <a href="https://openapi-generator.tech/" class="external-link" target="_blank">OpenAPI Generator</a>.

* <a href="https://github.com/tiangolo/full-stack-flask-couchdb" class="external-link" target="_blank">https://github.com/tiangolo/full-stack-flask-couchdb</a>

And these same full-stack generators were the base of the [**FastAPI** Project Generators](project-generation.md){.internal-link target=_blank}.

!!! info
    Flask-apispec was created by the same Marshmallow developers.

!!! check "Inspired **FastAPI** to"

* <a href="https://github.com/tiangolo/full-stack-flask-couchdb" class="external-link" target="_blank">https://github.com/tiangolo/full-stack-flask-couchdb</a>

そして、これらのフルスタックジェネレーターは、[**FastAPI** Project Generators](project-generation.md){.internal-link target=_blank}の元となっていました。

!!! info "情報"
    Flask-apispecはMarshmallowと同じ開発者により作成されました。

!!! check "**FastAPI**へ与えたインスピレーション"

## OpenAPI-Client-Generatoren

Es gibt viele Tools zum Generieren von Clients aus **OpenAPI**.

Ein gängiges Tool ist <a href="https://openapi-generator.tech/" class="external-link" target="_blank">OpenAPI Generator</a>.

Wenn Sie ein **Frontend** erstellen, ist <a href="https://github.com/hey-api/openapi-ts" class="external-link" target="_blank">openapi-ts</a> eine sehr interessante Alternative.

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

    これにより<a href="https://github.com/sorcio/async_exit_stack" class="external-link" target="_blank">async-exit-stack</a>と<a href="https://github.com/python-trio/async_generator" class="external-link" target="_blank">async-generator</a>がインストールされます。

!!! note "技術詳細"
    以下と一緒に使用できる関数なら何でも有効です:

```Python hl_lines="2  7  9"
{!../../../docs_src/custom_response/tutorial006c.py!}
```

### `StreamingResponse`

Nimmt einen asynchronen Generator oder einen normalen Generator/Iterator und streamt den Responsebody.

```Python hl_lines="2  14"
{!../../../docs_src/custom_response/tutorial007.py!}
```

#### Verwendung von `StreamingResponse` mit dateiähnlichen Objekten

    state["/async"] = "asyncgen started"
    yield state["/async"]
    state["/async"] = "asyncgen completed"


def generator_state(state: Dict[str, str] = Depends(get_state)):
    state["/sync"] = "generator started"
    yield state["/sync"]
    state["/sync"] = "generator completed"


async def asyncgen_state_try(state: Dict[str, str] = Depends(get_state)):
    state["/async_raise"] = "asyncgen raise started"

```

### `StreamingResponse`

Takes an async generator or a normal generator/iterator and streams the response body.

```Python hl_lines="2  14"
{!../../../docs_src/custom_response/tutorial007.py!}
```

#### Using `StreamingResponse` with file-like objects

If you have a file-like object (e.g. the object returned by `open()`), you can create a generator function to iterate over that file-like object.

It's possible to create a `list` of its items with `list(some_user.items)`.

But the object itself is not a `list`. And it's also not an actual Python <a href="https://docs.python.org/3/glossary.html#term-generator" class="external-link" target="_blank">generator</a>. Because of this, Pydantic doesn't know by default how to convert it to a `list` of Pydantic *models* / schemas.

    model_name_map = get_compat_model_name_map(all_fields)
    schema_generator = GenerateJsonSchema(ref_template=REF_TEMPLATE)
    field_mapping, definitions = get_definitions(
        fields=all_fields,
        schema_generator=schema_generator,
        model_name_map=model_name_map,
        separate_input_output_schemas=separate_input_output_schemas,
    )