from typing import Annotated, Union

from fastapi import FastAPI, Query

app = FastAPI()


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

from fastapi import FastAPI, Path, Query

app = FastAPI()


@app.get("/items/{item_id}")
async def read_items(
    *,
    item_id: Annotated[int, Path(title="The ID of the item to get", ge=0, le=1000)],
    q: str,
    size: Annotated[float, Query(gt=0, lt=10.5)],
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})
    if size:
        results.update({"size": size})

Se ele não ver o header de `Autorização` ou o valor não tem um token `Bearer`, vai responder com um código de erro  401 (`UNAUTHORIZED`) diretamente.

Você nem precisa verificar se o token existe para retornar um erro. Você pode ter certeza de que se a sua função for executada, ela terá um `str` nesse token.

Você já pode experimentar na documentação interativa:

from dirty_equals import IsDict
from fastapi import FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: Optional[str] = None


class ExtendedItem(Item):
    age: int


@app.post("/items/")
def save_union_different_body(item: Union[ExtendedItem, Item]):
    return {"item": item}


client = TestClient(app)

from typing import Annotated, Union

from fastapi import FastAPI, Query

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,
            max_length=50,

from fastapi import Depends, FastAPI

app = FastAPI()


fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}, {"item_name": "Baz"}]


class CommonQueryParams:
    def __init__(self, q: str | None = None, skip: int = 0, limit: int = 100):
        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")
async def read_items(commons=Depends(CommonQueryParams)):
    response = {}
    if commons.q:

from pydantic import BaseModel

app = FastAPI()


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


@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}


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

```Python hl_lines="11  13-14"
{!> ../../docs_src/response_model/tutorial004.py!}
```

////

* `description: Union[str, None] = None` (или `str | None = None` в Python 3.10), где `None` является значением по умолчанию.
* `tax: float = 10.5`, где `10.5` является значением по умолчанию.
* `tags: List[str] = []`, где пустой список `[]` является значением по умолчанию.

Sie können den `jsonable_encoder` verwenden, um die empfangenen Daten in etwas zu konvertieren, das als JSON gespeichert werden kann (in z. B. einer NoSQL-Datenbank). Zum Beispiel, um ein `datetime` in einen `str` zu konvertieren.

//// tab | Python 3.10+

```Python hl_lines="28-33"
{!> ../../docs_src/body_updates/tutorial001_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="30-35"

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

Ou como em Python 3.10 e versões superiores:

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

Por exemplo:

//// tab | Python 3.10+

```Python hl_lines="26"
{!> ../../docs_src/body_multiple_params/tutorial004_py310.py!}