'Whitelist' validation step. The parameter field will be the single one
            allowed by the alias or set of aliases defined.
            """
        ),
    ] = None,
    serialization_alias: Annotated[
        Union[str, None],
        Doc(
            """
            'Blacklist' validation step. The vanilla parameter field will be the
            single one of the alias' or set of aliases' fields and all the other

"English single typographic quotes"

    The characters «‘» and «’»
    Unicode U+2018 (LEFT SINGLE QUOTATION MARK) and Unicode U+2019 (RIGHT SINGLE QUOTATION MARK)

"code snippet"

    Also called "inline code". Text in a Markdown document which is surrounded by single backticks. A paragraph in a Markdown document can have a more than one code snippet.

### Quotes

1) Convert neutral double quotes («"») and English double typographic quotes («“» and «”») to German double typographic quotes («„» and «“»). Convert neutral single quotes («'») and English single typographic quotes («‘» and «’») to German single typographic quotes («‚» and «‘»). Do NOT convert «`"» to «„», do NOT convert «"`» to «“».

Examples:

    Source (English):

        «««
        "Hello world"

    # fields but it's the same one, so count them by name
    body_param_names_set = {field.name for field in fields}
    # A top level field has to be a single field, not multiple
    if len(body_param_names_set) > 1:
        return True
    first_field = fields[0]
    # If it explicitly specifies it is embedded, it has to be embedded

Just standard **Python**.

For example, for an `int`:

```Python
item_id: int
```

or for a more complex `Item` model:

```Python
item: Item
```

...and with that single declaration you get:

* Editor support, including:
    * Completion.
    * Type checks.
* Validation of data:
    * Automatic and clear errors when the data is invalid.

Just standard **Python**.

For example, for an `int`:

```Python
item_id: int
```

or for a more complex `Item` model:

```Python
item: Item
```

...and with that single declaration you get:

* Editor support, including:
    * Completion.
    * Type checks.
* Validation of data:
    * Automatic and clear errors when the data is invalid.

            Optional[Lifespan[Any]],
            Doc(
                """
                A `Lifespan` context manager handler. This replaces `startup` and
                `shutdown` functions with a single context manager.

                Read more in the
                [FastAPI docs for `lifespan`](https://fastapi.tiangolo.com/advanced/events/).
                """
            ),
        ] = None,

* ⬆ Bump tiangolo/issue-manager from 0.5.1 to 0.6.0. PR [#14148](https://github.com/fastapi/fastapi/pull/14148) by [@dependabot[bot]](https://github.com/apps/dependabot).
* 👷 Update docs previews comment, single comment, add failure status. PR [#14129](https://github.com/fastapi/fastapi/pull/14129) by [@tiangolo](https://github.com/tiangolo).

Sie können auch `response_model=None` verwenden, um das Erstellen eines Responsemodells für diese *Pfadoperation* zu unterbinden. Sie könnten das tun wollen, wenn Sie Dinge annotieren, die nicht gültige Pydantic-Felder sind. Ein Beispiel dazu werden Sie in einer der Abschnitte unten sehen.

## Dieselben Eingabedaten zurückgeben { #return-the-same-input-data }

* `$`: dort endet, keine weiteren Zeichen nach `fixedquery` hat.

Wenn Sie sich mit all diesen **„regulärer Ausdruck“**-Ideen verloren fühlen, keine Sorge. Sie sind ein schwieriges Thema für viele Menschen. Sie können noch viele Dinge tun, ohne reguläre Ausdrücke direkt zu benötigen.

Aber nun wissen Sie, dass Sie sie in **FastAPI** immer dann verwenden können, wenn Sie sie brauchen.

## Defaultwerte { #default-values }