@app.exception_handler(RequestValidationError)
async def validation_exception_handler(request: Request, exc: RequestValidationError):
    return JSONResponse(
        status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
        content=jsonable_encoder({"detail": exc.errors(), "body": exc.body}),
    )


class Item(BaseModel):
    title: str
    size: int


@app.post("/items/")
async def create_item(item: Item):

// qualify for replication and re-sync the object(s) to target, provided ExistingObjectReplication is
// enabled for the qualifying rule. This API is a MinIO only extension provided for situations where
// remote target is entirely lost,and previously replicated objects need to be re-synced. If resync is
// already in progress it returns an error

app = FastAPI()


@app.exception_handler(UnicornException)
async def unicorn_exception_handler(request: Request, exc: UnicornException):
    return JSONResponse(
        status_code=418,
        content={"message": f"Oops! {exc.name} did something. There goes a rainbow..."},
    )


@app.get("/unicorns/{name}")
async def read_unicorn(name: str):
    if name == "yolo":
        raise UnicornException(name=name)

///

## `async`にするかどうか

依存関係は **FastAPI**（*path operation関数*と同じ）からも呼び出されるため、関数を定義する際にも同じルールが適用されます。

`async def`や通常の`def`を使用することができます。

また、通常の`def`*path operation関数*の中に`async def`を入れて依存関係を宣言したり、`async def`*path operation関数*の中に`def`を入れて依存関係を宣言したりすることなどができます。

それは重要ではありません。**FastAPI** は何をすべきかを知っています。

/// note | "備考"

from fastapi.testclient import TestClient

app = FastAPI()


@app.get("/users/{user_id}")
async def get_user(user_id: str, request: Request):
    route: APIRoute = request.scope["route"]
    return {"user_id": user_id, "path": route.path}


@app.websocket("/items/{item_id}")
async def websocket_item(item_id: str, websocket: WebSocket):
    route: APIWebSocketRoute = websocket.scope["route"]

@app.get(
    "/a",
    response_class=Response,
    responses={500: {"description": "Error", "model": JsonApiError}},
)
async def a():
    pass  # pragma: no cover


@app.get("/b", responses={500: {"description": "Error", "model": Error}})
async def b():
    pass  # pragma: no cover


client = TestClient(app)


def test_openapi_schema():
    response = client.get("/openapi.json")

package ioutil

import (
	"io"
	"os"
)

// AppendFile - appends the file "src" to the file "dst"
func AppendFile(dst string, src string, osync bool) error {
	flags := os.O_WRONLY | os.O_APPEND | os.O_CREATE
	if osync {
		flags |= os.O_SYNC
	}
	appendFile, err := os.OpenFile(dst, flags, 0o666)
	if err != nil {
		return err
	}
	defer appendFile.Close()

	srcFile, err := os.Open(src)

    ```python
    from fastapi import Depends, FastAPI
    from fastapi.security import APIKeyQuery

    app = FastAPI()

    query_scheme = APIKeyQuery(name="api_key")


    @app.get("/items/")
    async def read_items(api_key: str = Depends(query_scheme)):
        return {"api_key": api_key}
    ```
    """

    def __init__(
        self,
        *,
        name: Annotated[
            str,

## `async` oder nicht `async`

Da Abhängigkeiten auch von **FastAPI** aufgerufen werden (so wie Ihre *Pfadoperation-Funktionen*), gelten beim Definieren Ihrer Funktionen die gleichen Regeln.

Sie können `async def` oder einfach `def` verwenden.

):
    return [item, sub_item]


@app.post("/with-duplicates")
async def with_duplicates(item: Item, item2: Item = Depends(duplicate_dependency)):
    return [item, item2]


@app.post("/no-duplicates")
async def no_duplicates(item: Item, item2: Item = Depends(dependency)):
    return [item, item2]


@app.post("/with-duplicates-sub")
async def no_duplicates_sub(