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": []},
}

                            # TODO: remove when deprecating Pydantic v1
                            {"title": "Description", "type": "string"}
                        ),
                        "tax": {"title": "Tax", "type": "number", "default": 10.5},
                    },
                },
                "ValidationError": {
                    "title": "ValidationError",

                            # TODO: remove when deprecating Pydantic v1
                            {"title": "Description", "type": "string"}
                        ),
                        "tax": {"title": "Tax", "type": "number", "default": 10.5},
                    },
                },
                "ValidationError": {
                    "title": "ValidationError",

    name: str
    description: str | None = None
    price: float
    tax: float | None = None

    model_config = {
        "json_schema_extra": {
            "examples": [
                {
                    "name": "Foo",
                    "description": "A very nice Item",
                    "price": 35.4,
                    "tax": 3.2,
                }
            ]
        }
    }

    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: Item = Body(
        examples=[
            {
                "name": "Foo",
                "description": "A very nice Item",
                "price": 35.4,
                "tax": 3.2,
            }
        ],
    ),
):

                        ),
                        "price": {"title": "Price", "type": "number"},
                        "tax": IsDict(
                            {
                                "title": "Tax",
                                "anyOf": [{"type": "number"}, {"type": "null"}],
                            }
                        )
                        | IsDict(

    price: float
    tax: Union[float, None] = None
    tags: set[str] = set()


@app.post("/items/", response_model=Item, summary="Create an item")
async def create_item(item: Item):
    """
    Create an item with all the information:

    - **name**: each item must have a name
    - **description**: a long description
    - **price**: required
    - **tax**: if the item doesn't have tax, you can omit this

                        },
                        "price": {"type": "number", "title": "Price"},
                        "tax": {
                            "anyOf": [{"type": "number"}, {"type": "null"}],
                            "title": "Tax",
                        },
                    },
                    "type": "object",
                    "required": ["name", "price"],

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(
            openapi_examples={

    name: str | None = None
    description: str | None = None
    price: float | None = None
    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": []},
}


@app.get("/items/{item_id}", response_model=Item)