item = {"item_id": item_id}
    if q:
        item.update({"q": q})
    if not short:
        item.update(
            {"description": "This is an amazing item that has a long description"}
        )

from fastapi import FastAPI
from pydantic import BaseModel as BaseModelV2
from pydantic.v1 import BaseModel


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


class ItemV2(BaseModelV2):
    name: str
    description: str | None = None
    size: float


app = FastAPI()


@app.post("/items/", response_model=ItemV2)
async def create_item(item: Item):

app = FastAPI()


@app.post("/files/")
async def create_file(file: Annotated[bytes, File(description="A file read as bytes")]):
    return {"file_size": len(file)}


@app.post("/uploadfile/")
async def create_upload_file(
    file: Annotated[UploadFile, File(description="A file read as UploadFile")],
):

    stage: Stage,
    bucketIndex: Int,
    description: String,
    tests: Map<String, List<Scenario>>,
): PerformanceTest {
    val descriptionWithMaybeBucketIndex =
        if (performanceTestCoverage.type == PerformanceTestType.FLAKINESS_DETECTION) {
            "$description - index $bucketIndex"
        } else {
            description
        }
    return PerformanceTest(
        model,

  private final char[] table;
  private final boolean containsZero;
  private final long filter;

  private SmallCharMatcher(char[] table, long filter, boolean containsZero, String description) {
    super(description);
    this.table = table;
    this.filter = filter;
    this.containsZero = containsZero;
  }

  private static final int C1 = 0xcc9e2d51;
  private static final int C2 = 0x1b873593;

  /*

                        "responses": {
                            "200": {
                                "description": "Successful Response",
                                "content": {"application/json": {"schema": {}}},
                            },
                            "422": {
                                "description": "Validation Error",
                                "content": {

                            }
                        ],
                        "responses": {
                            "204": {"description": "Successful Response"},
                            "422": {
                                "description": "Validation Error",
                                "content": {
                                    "application/json": {

    message: str


app = FastAPI()


@app.get(
    "/items/{item_id}",
    response_model=Item,
    responses={
        404: {"model": Message, "description": "The item was not found"},
        200: {
            "description": "Item requested by ID",
            "content": {
                "application/json": {
                    "example": {"id": "bar", "value": "The bar tenders"}
                }

在此情況下 **FastAPI** 會期望如下的主體：

```JSON hl_lines="2"
{
    "item": {
        "name": "Foo",
        "description": "The pretender",
        "price": 42.0,
        "tax": 3.2
    }
}
```

而不是：

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2
}
```

## 小結 { #recap }

                * `description`: A short description of the tag.
                    [CommonMark syntax](https://commonmark.org/) MAY be used for rich
                    text representation.
                * `externalDocs`: Additional external documentation for this tag. If
                    provided, it would contain a `dict` with:
                    * `description`: A short description of the target documentation.