```Python
q: str
```

statt:

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

Aber jetzt deklarieren wir den Parameter mit `Query`, wie in:

//// tab | Annotiert

```Python
q: Annotated[Union[str, None], Query(min_length=3)] = None
```

////

//// tab | Nicht annotiert

```Python
q: Union[str, None] = Query(default=None, min_length=3)
```

////

pkg go/types, method (*TypeParamList) At(int) *TypeParam
pkg go/types, method (*TypeParamList) Len() int
pkg go/types, method (*Union) Len() int
pkg go/types, method (*Union) String() string
pkg go/types, method (*Union) Term(int) *Term
pkg go/types, method (*Union) Underlying() Type
pkg go/types, type ArgumentError struct
pkg go/types, type ArgumentError struct, Err error
pkg go/types, type ArgumentError struct, Index int

/// note | Hinweis

## Приклад

### Створіть

* Створіть файл `main.py` з:

```Python
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">

## `Union` ou `anyOf`

Você pode declarar uma resposta como o `Union` de dois tipos, o que significa que a resposta seria qualquer um dos dois.

Isso será definido no OpenAPI com `anyOf`.

Para fazer isso, use a dica de tipo padrão do Python <a href="https://docs.python.org/3/library/typing.html#typing.Union" class="external-link" target="_blank">`typing.Union`</a>:

/// note

## `Union` или `anyOf`

Вы можете определить ответ как `Union` из двух типов. Это означает, что ответ должен соответствовать одному из них.

Он будет определён в OpenAPI как `anyOf`.

Для этого используйте стандартные аннотации типов в Python <a href="https://docs.python.org/3/library/typing.html#typing.Union" class="external-link" target="_blank">`typing.Union`</a>:

/// note | Примечание

```

////

#### Using `Union` or `Optional` { #using-union-or-optional }

If you are using a Python version below 3.10, here's a tip from my very **subjective** point of view:

* 🚨 Avoid using `Optional[SomeType]`
* Instead ✨ **use `Union[SomeType, None]`** ✨.

import static com.google.common.collect.Multisets.difference;
import static com.google.common.collect.Multisets.intersection;
import static com.google.common.collect.Multisets.sum;
import static com.google.common.collect.Multisets.union;
import static com.google.common.collect.Multisets.unmodifiableMultiset;
import static java.util.Arrays.asList;
import static java.util.Collections.sort;

import com.google.common.annotations.GwtIncompatible;

{* ../../docs_src/extra_models/tutorial002_py310.py hl[7,13:14,17:18,21:22] *}

## `Union` 또는 `anyOf`

두 가지 이상의 타입을 포함하는 `Union`으로 응답을 선언할 수 있습니다. 이는 응답이 그 중 하나의 타입일 수 있음을 의미합니다.

OpenAPI에서는 이를 `anyOf`로 정의합니다.

이를 위해 표준 Python 타입 힌트인 <a href="https://docs.python.org/3/library/typing.html#typing.Union" class="external-link" target="_blank">`typing.Union`</a>을 사용할 수 있습니다:

/// note | 참고

	typedef struct {
		int count;
		[size_is(count)] ShareInfo502 *array;
	} ShareInfoCtr502;

	typedef [switch_type(int)] union {
		[case(0)] ShareInfo0 *info0;
		[case(1)] ShareInfo1 *info1;
		[case(502)] ShareInfo502 *info1;
	} ShareInfo;

	typedef [switch_type(int)] union {
		[case(0)] ShareInfoCtr0 *info0;
		[case(1)] ShareInfoCtr1 *info1;
		[case(502)] ShareInfoCtr502 *info1;
	} ShareCtr;

	[op(0x0f)]