}
```

🔄, ⚫️ 🔜 🗜 📊 🆎, ✔, 📄, ♒️.

## 💗 💪 = & 🔢

↗️, 👆 💪 📣 🌖 🔢 🔢 🕐❔ 👆 💪, 🌖 🙆 💪 🔢.

, 🔢, ⭐ 💲 🔬 🔢 🔢, 👆 🚫 ✔️ 🎯 🚮 `Query`, 👆 💪:

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

⚖️ 🐍 3️⃣.1️⃣0️⃣ & 🔛:

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

🖼:

=== "🐍 3️⃣.6️⃣ & 🔛"

    ```Python hl_lines="27"

As, by default, singular values are interpreted as query parameters, you don't have to explicitly add a `Query`, you can just do:

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

Or in Python 3.10 and above:

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

For example:

=== "Python 3.10+"

    ```Python hl_lines="27"

### ❌ 📨 🆎 ✍

✋️ 🕐❔ 👆 📨 🎏 ❌ 🎚 👈 🚫 ☑ Pydantic 🆎 (✅ 💽 🎚) & 👆 ✍ ⚫️ 💖 👈 🔢, FastAPI 🔜 🔄 ✍ Pydantic 📨 🏷 ⚪️➡️ 👈 🆎 ✍, & 🔜 ❌.

🎏 🔜 🔨 🚥 👆 ✔️ 🕳 💖 <abbr title='A union between multiple types means "any of these types".'>🇪🇺</abbr> 🖖 🎏 🆎 🌐❔ 1️⃣ ⚖️ 🌅 👫 🚫 ☑ Pydantic 🆎, 🖼 👉 🔜 ❌ 👶:

=== "🐍 3️⃣.6️⃣ &amp; 🔛"

    ```Python hl_lines="10"

* 빈 파일 `__init__.py`을 생성합니다.
* 다음과 같은 `main.py`을 생성합니다:

```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}
```

### 도커파일

```Python
from typing import Union
from fastapi import Cookie, FastAPI, Header, Path, Query

app = FastAPI()


@app.get("/items/{item_id}")
def main(
    item_id: int = Path(gt=0),
    query: Union[str, None] = Query(default=None, max_length=10),
    session: Union[str, None] = Cookie(default=None, min_length=3),
    x_trace: Union[str, None] = Header(default=None, title="Tracing header"),

    ```

## `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"

    ```

## `Union` or `anyOf`

You can declare a response to be the `Union` of two types, that means, that the response would be any of the two.

It will be defined in OpenAPI with `anyOf`.

To do that, use the standard Python type hint <a href="https://docs.python.org/3/library/typing.html#typing.Union" class="external-link" target="_blank">`typing.Union`</a>:

!!! note

    ```

#### ⚙️ `Union` ⚖️ `Optional`

🚥 👆 ⚙️ 🐍 ⏬ 🔛 3️⃣.1️⃣0️⃣, 📥 💁‍♂ ⚪️➡️ 👇 📶 **🤔** ☝ 🎑:

* 👶 ❎ ⚙️ `Optional[SomeType]`
* ↩️ 👶 **⚙️ `Union[SomeType, None]`** 👶.

👯‍♂️ 🌓 & 🔘 👫 🎏, ✋️ 👤 🔜 👍 `Union` ↩️ `Optional` ↩️ 🔤 "**📦**" 🔜 😑 🔑 👈 💲 📦, & ⚫️ 🤙 ⛓ "⚫️ 💪 `None`", 🚥 ⚫️ 🚫 📦 & ✔.

👤 💭 `Union[SomeType, None]` 🌖 🔑 🔃 ⚫️❔ ⚫️ ⛓.

    ```

The query parameter `q` is of type `Union[str, None]` (or `str | None` in Python 3.10), that means that it's of type `str` but could also be `None`, and indeed, the default value is `None`, so FastAPI will know it's not required.

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

## Exemplo

### Crie

* Crie um arquivo `main.py` com:

```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">