from typing import Union

from fastapi import FastAPI, Header
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: Annotated[Union[str, None], Header()] = None):

from typing import List, Union

from fastapi import FastAPI, Header
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/")
async def read_items(x_token: Annotated[Union[List[str], None], Header()] = None):

from typing import Union

from fastapi import Body, FastAPI
from pydantic import BaseModel, Field
from typing_extensions import Annotated

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = Field(
        default=None, title="The description of the item", max_length=300
    )
    price: float = Field(gt=0, description="The price must be greater than zero")
    tax: Union[float, None] = None

from typing import Union

from fastapi import Body, FastAPI
from pydantic import BaseModel
from typing_extensions import Annotated

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None


class User(BaseModel):
    username: str
    full_name: Union[str, None] = None


@app.put("/items/{item_id}")
async def update_item(

from typing import Union

from fastapi import FastAPI, Query
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/")
async def read_items(
    q: Annotated[
        Union[str, None],
        Query(
            alias="item-query",
            title="Query string",
            description="Query string for the items to search in the database that have a good match",
            min_length=3,

    /**
     * Gets the model being built. The precise state of this model depends on the event being fired.
     *
     * @return The model being built, never {@code null}.
     */
    Model model();

    Consumer<Model> update();

    /**
     * Gets the model building request being processed.
     *
     * @return The model building request being processed, never {@code null}.
     */

OpenAPIでは`anyOf`で定義されます。

そのためには、標準的なPythonの型ヒント<a href="https://docs.python.org/3/library/typing.html#typing.Union" class="external-link" target="_blank">`typing.Union`</a>を使用します:

```Python hl_lines="1 14 15 18 19 20 33"
{!../../../docs_src/extra_models/tutorial003.py!}
```

## モデルのリスト

同じように、オブジェクトのリストのレスポンスを宣言することができます。

そのためには、標準のPythonの`typing.List`を使用する:

```Python hl_lines="1 20"

from typing import Union

from fastapi import Body, FastAPI
from pydantic import BaseModel
from typing_extensions import Annotated

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,
    item: Annotated[
        Item,
        Body(

```

### 3.2 Automatic removal of noncurrent versions keeping only most recent ones after noncurrent days

It is possible to configure automatic removal of older noncurrent versions keeping only the most recent `N` using `NewerNoncurrentVersions`.

e.g, To remove noncurrent versions of all objects keeping the most recent 5 noncurrent versions under the prefix `user-uploads/` 30 days after they become noncurrent ,

 * object being tested for equality to the custom interface. {@code ForwardingObject} implements no
 * such custom interfaces directly; they are implemented only in subclasses. Therefore, forwarding
 * {@code equals} would break symmetry, as the forwarding object might consider itself equal to the
 * object being tested, but the reverse could not be true. This behavior is consistent with the