* `externalDocs`: `dict` 🔬 🔢 🧾 ⏮️:
    * `description`: `str` ⏮️ 📏 📛 🔢 🩺.
    * `url` (**✔**): `str` ⏮️ 📛 🔢 🧾.

### ✍ 🗃 🔖

➡️ 🔄 👈 🖼 ⏮️ 🔖 `users` & `items`.

✍ 🗃 👆 🔖 & 🚶‍♀️ ⚫️ `openapi_tags` 🔢:

```Python hl_lines="3-16  18"
{!../../docs_src/metadata/tutorial004.py!}
```

👀 👈 👆 💪 ⚙️ ✍ 🔘 📛, 🖼 "💳" 🔜 🎦 🦁 (**💳**) & "🎀" 🔜 🎦 ❕ (_🎀_).

                    "properties": {
                        "loc": {
                            "title": "Location",
                            "type": "array",
                            "items": {
                                "anyOf": [{"type": "string"}, {"type": "integer"}]
                            },
                        },
                        "msg": {"title": "Message", "type": "string"},

                        "properties": {
                            "detail": {
                                "title": "Detail",
                                "type": "array",
                                "items": {
                                    "$ref": "#/components/schemas/ValidationError"
                                },
                            }
                        },
                    },

  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.ListMeta metadata = 1;

  // items is a list of schema objects.
  repeated RuntimeClass items = 2;
}

// Scheduling specifies the scheduling constraints for nodes supporting a
// RuntimeClass.
message Scheduling {

## Example

```python
from fastapi import FastAPI, status

app = FastAPI()


@app.get("/items/", status_code=status.HTTP_418_IM_A_TEAPOT)
def read_items():
    return [{"name": "Plumbus"}, {"name": "Portal Gun"}]
```

from pydantic import BaseModel

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: Item = Body(
        openapi_examples={
            "normal": {
                "summary": "A normal example",

from datetime import datetime, time, timedelta
from uuid import UUID

from fastapi import Body, FastAPI

app = FastAPI()


@app.put("/items/{item_id}")
async def read_items(
    item_id: UUID,
    start_datetime: datetime = Body(),
    end_datetime: datetime = Body(),
    process_after: timedelta = Body(),
    repeat_at: time | None = Body(default=None),
):
    start_process = start_datetime + process_after

from typing import Annotated

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})

CONTAINER_OPTIONS = --mount type=bind,source=/tmp,destination=/tmp --net=host

export COMMONFILES_POSTPROCESS = tools/commonfiles-postprocess.sh

ifeq ($(BUILD_WITH_CONTAINER),1)
# create phony targets for the top-level items in the repo
PHONYS := $(shell ls | grep -v Makefile)
.PHONY: $(PHONYS)
$(PHONYS):
	@$(MAKE_DOCKER) $@
endif

# istioctl-install builds then installs istioctl into $GOPATH/BIN

    description: Union[str, None] = Field(default=None, examples=["A very nice Item"])
    price: float = Field(examples=[35.4])
    tax: Union[float, None] = Field(default=None, examples=[3.2])


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