# 高级 Python 类型 { #advanced-python-types }

这里有一些在使用 Python 类型时可能有用的额外想法。

## 使用 `Union` 或 `Optional` { #using-union-or-optional }

如果你的代码因为某些原因不能使用 `|`，例如它不是在类型注解里，而是在 `response_model=` 之类的参数中，那么你可以使用 `typing` 中的 `Union` 来代替竖线（`|`）。

例如，你可以声明某个值可以是 `str` 或 `None`：

```python
from typing import Union


def say_hi(name: Union[str, None]):
        print(f"Hi {name}!")
```

`typing` 也提供了一个声明“可能为 `None`”的快捷方式：`Optional`。

# 高度な Python の型 { #advanced-python-types }

Python の型を扱うときに役立つ追加のアイデアをいくつか紹介します。

## `Union` または `Optional` の利用 { #using-union-or-optional }

何らかの理由で `|` が使えない場合、たとえば型アノテーションではなく `response_model=` のような場所では、縦棒（`|`）の代わりに `typing` の `Union` を使えます。

例えば、`str` または `None` になり得ることを宣言できます:

```python
from typing import Union


def say_hi(name: Union[str, None]):
        print(f"Hi {name}!")
```

        return True
    origin = get_origin(annotation)
    if origin is Union or origin is UnionType:
        for arg in get_args(annotation):
            if lenient_issubclass(arg, UploadFile):
                return True
    return False


def is_bytes_sequence_annotation(annotation: Any) -> bool:
    origin = get_origin(annotation)
    if origin is Union or origin is UnionType:
        at_least_one = False

## `Union` or `anyOf` { #union-or-anyof }

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

It will be defined in OpenAPI with `anyOf`.

To do that, use the standard Python type hint [`typing.Union`](https://docs.python.org/3/library/typing.html#typing.Union):

/// note

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

If your code for some reason can't use `|`, for example if it's not in a type annotation but in something like `response_model=`, instead of using the vertical bar (`|`) you can use `Union` from `typing`.

For example, you could declare that something could be a `str` or `None`:

```python
from typing import Union


def say_hi(name: Union[str, None]):

                                    "application/json": {
                                        "schema": {
                                            "title": "Response Response Model Union No Annotation Return Model1 Response Model Union No Annotation Return Model1 Get",
                                            "anyOf": [
                                                {"$ref": "#/components/schemas/User"},

# 進階 Python 型別 { #advanced-python-types }

以下是一些在使用 Python 型別時可能有用的額外想法。

## 使用 `Union` 或 `Optional` { #using-union-or-optional }

如果你的程式碼因某些原因無法使用 `|`，例如不是在型別註記中，而是在像 `response_model=` 之類的參數位置，那麼你可以用 `typing` 中的 `Union` 來取代豎線（`|`）。

例如，你可以宣告某個值可以是 `str` 或 `None`：

```python
from typing import Union


def say_hi(name: Union[str, None]):
        print(f"Hi {name}!")
```

在 `typing` 中也有用 `Optional` 宣告某個值可以是 `None` 的速記法。

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

## `Union` 或 `anyOf` { #union-or-anyof }

你可以將回應宣告為多個型別的 `Union`，表示回應可能是其中任一型別。

在 OpenAPI 中會以 `anyOf` 定義。

要達成這點，使用標準的 Python 型別提示 [`typing.Union`](https://docs.python.org/3/library/typing.html#typing.Union)：

/// note

import types
from collections.abc import Callable
from enum import Enum
from typing import Any, TypeVar, Union

from pydantic import BaseModel
from pydantic.main import IncEx as IncEx

DecoratedCallable = TypeVar("DecoratedCallable", bound=Callable[..., Any])
UnionType = getattr(types, "UnionType", Union)
ModelNameMap = dict[type[BaseModel] | type[Enum], str]

#### Union { #union }

You can declare that a variable can be any of **several types**, for example, an `int` or a `str`.

To define it you use the <dfn title='also called "bitwise or operator", but that meaning is not relevant here'>vertical bar (`|`)</dfn> to separate both types.

This is called a "union", because the variable can be anything in the union of those two sets of types.