assert response.json() == {
        "detail": [
            {
                "type": "missing",
                "loc": ["query", "p"],
                "msg": "Field required",
                "input": IsOneOf(None, {}),
            }
        ]
    }


@pytest.mark.parametrize(
    "path",
    ["/required-list-str", "/model-required-list-str"],
)
def test_required_list_str(path: str):
    client = TestClient(app)

from fastapi import Cookie, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Cookies(BaseModel):
    session_id: str
    fatebook_tracker: str | None = None
    googall_tracker: str | None = None


@app.get("/items/")
async def read_items(cookies: Cookies = Cookie()):

```

////

In beiden Fällen bedeutet das, dass `item` ein `int` oder ein `str` sein kann.

#### Vielleicht `None` { #possibly-none }

Sie können deklarieren, dass ein Wert ein `str`, aber vielleicht auch `None` sein kann.

In Python 3.6 und darüber (inklusive Python 3.10) können Sie das deklarieren, indem Sie `Optional` vom `typing` Modul importieren und verwenden.

    print("LLM translatable languages:", translatable_langs)
    return translatable_langs


@app.command()
def llm_translatable_json(
    language: Annotated[str | None, typer.Option(envvar="LANGUAGE")] = None,
) -> None:
    translatable_langs = get_llm_translatable()
    if language:
        if language in translatable_langs:
            print(json.dumps([language]))
            return
        else:

from fastapi import FastAPI
from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


app = FastAPI()


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

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    host: str
    save_data: bool
    if_modified_since: str | None = None
    traceparent: str | None = None
    x_tag: list[str] = []


@app.get("/items/")
async def read_items(headers: Annotated[CommonHeaders, Header()]):

from fastapi import FastAPI, status
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None
    tags: set[str] = set()


@app.post("/items/", response_model=Item, status_code=status.HTTP_201_CREATED)
async def create_item(item: Item):

async def override_dependency(q: str | None = None):
    return {"q": q, "skip": 5, "limit": 10}


app.dependency_overrides[common_parameters] = override_dependency


def test_override_in_items():
    response = client.get("/items/")
    assert response.status_code == 200
    assert response.json() == {
        "message": "Hello Items!",
        "params": {"q": None, "skip": 5, "limit": 10},
    }

  Just as she said this, she noticed that one of the trees had a
door leading right into it.  `That's very curious!' she thought.
`But everything's curious today.  I think I may as well go in at once.'
And in she went.

  Once more she found herself in the long hall, and close to the
little glass table.  `Now, I'll manage better this time,'
she said to herself, and began by taking the little golden key,

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float = 10.5
    tags: list[str] = []


items = {
    "foo": {"name": "Foo", "price": 50.2},
    "bar": {"name": "Bar", "description": "The bartenders", "price": 62, "tax": 20.2},
    "baz": {"name": "Baz", "description": None, "price": 50.2, "tax": 10.5, "tags": []},
}