/// note

FastAPI will know that the value of `q` is not required because of the default value `= None`.

The `str | None` (Python 3.10+) or `Union` in `Union[str, None]` (Python 3.9+) is not used by FastAPI to determine that the value is not required, it will know it's not required because it has a default value of `= None`.

```Python
q: str | None = None
```

////

//// tab | Python 3.9+

```Python
q: Union[str, None] = None
```

////

What we will do is wrap that with `Annotated`, so it becomes:

//// tab | Python 3.10+

```Python
q: Annotated[str | None] = None
```

////

//// tab | Python 3.9+

```Python
q: Annotated[Union[str, None]] = None
```

////

/// note | Nota

O FastAPI saberá que o valor de `q` não é obrigatório por causa do valor padrão `= None`.

O `str | None` (Python 3.10+) ou o `Union` em `Union[str, None]` (Python 3.9+) não é utilizado pelo FastAPI para determinar que o valor não é obrigatório, ele saberá que não é obrigatório porque tem um valor padrão `= None`.

Sie haben es eilig und kennen sich bereits aus? Springen Sie zum [`Dockerfile` unten 👇](#build-a-docker-image-for-fastapi).

///

<details>
<summary>Dockerfile-Vorschau 👀</summary>

```Dockerfile
FROM python:3.9

WORKDIR /code

COPY ./requirements.txt /code/requirements.txt

RUN pip install --no-cache-dir --upgrade -r /code/requirements.txt

COPY ./app /code/app

CMD ["fastapi", "run", "app/main.py", "--port", "80"]

/// note | Nota

FastAPI sabrá que el valor de `q` no es requerido debido al valor por defecto `= None`.

El `str | None` (Python 3.10+) o `Union` en `Union[str, None]` (Python 3.9+) no es utilizado por FastAPI para determinar que el valor no es requerido, sabrá que no es requerido porque tiene un valor por defecto de `= None`.

/// note | Заметка

FastAPI понимает, что значение `q` не является обязательным из-за значения по умолчанию `= None`.

Аннотации типов `str | None` (Python 3.10+) или `Union[str, None]` (Python 3.9+) не используются FastAPI для определения обязательности; он узнает, что параметр не обязателен, потому что у него есть значение по умолчанию `= None`.

pkg debug/elf, const R_386_TLS_DESC = 41
pkg debug/elf, const R_386_TLS_DESC R_386
pkg debug/elf, const R_386_TLS_DESC_CALL = 40
pkg debug/elf, const R_386_TLS_DESC_CALL R_386
pkg debug/elf, const R_386_TLS_GOTDESC = 39
pkg debug/elf, const R_386_TLS_GOTDESC R_386
pkg debug/elf, const R_AARCH64_LD64_GOTOFF_LO15 = 310
pkg debug/elf, const R_AARCH64_LD64_GOTOFF_LO15 R_AARCH64
pkg debug/elf, const R_AARCH64_LD64_GOTPAGE_LO15 = 313

두 *경로 작업* 모두 `X-Token` 헤더를 요구합니다.

//// tab | Python 3.10+

```Python
{!> ../../docs_src/app_testing/app_b_an_py310/main.py!}
```

////

//// tab | Python 3.9+

```Python
{!> ../../docs_src/app_testing/app_b_an_py39/main.py!}
```

////

//// tab | Python 3.8+

```Python
{!> ../../docs_src/app_testing/app_b_an/main.py!}
```

////

	_ = x[ErrNoSuchBucket-34]
	_ = x[ErrNoSuchBucketPolicy-35]
	_ = x[ErrNoSuchBucketLifecycle-36]
	_ = x[ErrNoSuchLifecycleConfiguration-37]
	_ = x[ErrInvalidLifecycleWithObjectLock-38]
	_ = x[ErrNoSuchBucketSSEConfig-39]
	_ = x[ErrNoSuchCORSConfiguration-40]
	_ = x[ErrNoSuchWebsiteConfiguration-41]
	_ = x[ErrReplicationConfigurationNotFoundError-42]
	_ = x[ErrRemoteDestinationNotFoundError-43]
	_ = x[ErrReplicationDestinationMissingLock-44]

```Python
q: str | None = None
```

////

//// tab | Python 3.9+

```Python
q: Union[str, None] = None
```

////

Lo que haremos es envolver eso con `Annotated`, para que se convierta en:

//// tab | Python 3.10+

```Python
q: Annotated[str | None] = None
```

////

//// tab | Python 3.9+

```Python
q: Annotated[Union[str, None]] = None
```

////