Ich denke, `Union[SomeType, None]` ist expliziter bezüglich seiner Bedeutung.

Es geht nur um Wörter und Namen. Aber diese Worte können beeinflussen, wie Sie und Ihre Teamkollegen über den Code denken.

Nehmen wir zum Beispiel diese Funktion:

```Python hl_lines="1  4"
{!../../../docs_src/python_types/tutorial009c.py!}

🕐❔ 👆 💚 🤙 `async def` 🔢, 👆 ✔️ "⌛" ⚫️. , 👉 🏆 🚫 👷:

```Python
# This won't work, because get_burgers was defined with: async def
burgers = get_burgers(2)
```

---

, 🚥 👆 ⚙️ 🗃 👈 💬 👆 👈 👆 💪 🤙 ⚫️ ⏮️ `await`, 👆 💪 ✍ *➡ 🛠️ 🔢* 👈 ⚙️ ⚫️ ⏮️ `async def`, 💖:

```Python hl_lines="2-3"
@app.get('/burgers')

The same way, when reading a user, we can now declare that `items` will contain the items that belong to this user.

Not only the IDs of those items, but all the data that we defined in the Pydantic *model* for reading items: `Item`.

=== "Python 3.10+"

    ```Python hl_lines="13-15  29-32"
    {!> ../../../docs_src/sql_databases/sql_app_py310/schemas.py!}
    ```

=== "Python 3.9+"

        * `password`: some next chapters will cover examples of this.
* `openIdConnect`: has a way to define how to discover OAuth2 authentication data automatically.
    * This automatic discovery is what is defined in the OpenID Connect specification.


!!! tip
    Integrating other authentication/authorization providers like Google, Facebook, Twitter, GitHub, etc. is also possible and relatively easy.

    """

    def __init__(
        self,
        code: Annotated[
            int,
            Doc(
                """
                A closing code from the
                [valid codes defined in the specification](https://datatracker.ietf.org/doc/html/rfc6455#section-7.4.1).
                """
            ),
        ],
        reason: Annotated[
            Union[str, None],
            Doc(

  docs-all-green:  # This job does nothing and is only used for the branch protection
    if: always()
    needs:
      - build-docs
    runs-on: ubuntu-latest
    steps:
      - name: Decide whether the needed jobs succeeded or failed
        uses: re-actors/alls-green@release/v1
        with:
          jobs: ${{ toJSON(needs) }}

The dictionary in `openapi_extra` will be deeply merged with the automatically generated OpenAPI schema for the *path operation*.

So, you could add additional data to the automatically generated schema.

For example, you could decide to read and validate the request with your own code, without using the automatic features of FastAPI with Pydantic, but you could still want to define the request in the OpenAPI schema.

You could do that with `openapi_extra`:

        # TODO: remove when deprecating Pydantic v1
        encoders: Dict[Any, Any] = {}
        if not PYDANTIC_V2:
            encoders = getattr(obj.__config__, "json_encoders", {})  # type: ignore[attr-defined]
            if custom_encoder:
                encoders.update(custom_encoder)
        obj_dict = _model_dump(
            obj,
            mode="json",
            include=include,

* Security - HTTPS
* Running on startup
* Restarts
* Replication (the number of processes running)
* Memory
* Previous steps before starting

## Memory

                    corresponding JSON.
                * Filtering: the JSON sent to the client will only contain the data
                    (fields) defined in the `response_model`. If you returned an object
                    that contains an attribute `password` but the `response_model` does
                    not include that field, the JSON sent to the client would not have