from fastapi.testclient import TestClient


class CustomError(Exception):
    pass


def catching_dep() -> Any:
    try:
        yield "s"
    except CustomError as err:
        raise HTTPException(status_code=418, detail="Session error") from err


def broken_dep() -> Any:
    yield "s"
    raise ValueError("Broken after yield")


app = FastAPI()


@app.get("/catching")

        self.name = name


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":

app.include_router(users.router)
app.include_router(items.router)
app.include_router(
    admin.router,
    prefix="/admin",
    tags=["admin"],
    dependencies=[Depends(get_token_header)],
    responses={418: {"description": "I'm a teapot"}},
)


@app.get("/")
async def root():

    return await request_validation_exception_handler(request, exc)


@app.get("/items/{item_id}")
async def read_item(item_id: int):
    if item_id == 3:
        raise HTTPException(status_code=418, detail="Nope! I don't like 3.")

Here, if you request `/unicorns/yolo`, the *path operation* will `raise` a `UnicornException`.

But it will be handled by the `unicorn_exception_handler`.

So, you will receive a clean error, with an HTTP status code of `418` and a JSON content of:

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}
```

/// note | Technical Details

    return PlainTextResponse(message, status_code=400)


@app.get("/items/{item_id}")
async def read_item(item_id: int):
    if item_id == 3:
        raise HTTPException(status_code=418, detail="Nope! I don't like 3.")

Burada `/unicorns/yolo` için request atarsanız, *path operation* bir `UnicornException` `raise` eder.

Namun bu, `unicorn_exception_handler` tarafından handle edilir.

Böylece HTTP status code’u `418` olan, JSON içeriği şu şekilde temiz bir hata response’u alırsınız:

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}
```

/// note | Teknik Detaylar

Aquí, si solicitas `/unicorns/yolo`, la *path operation* lanzará un `UnicornException`.

Pero será manejado por el `unicorn_exception_handler`.

Así que recibirás un error limpio, con un código de estado HTTP de `418` y un contenido JSON de:

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}
```

/// note | Nota Técnica

{* ../../docs_src/handling_errors/tutorial003_py310.py hl[5:7,13:18,24] *}

这里，请求 `/unicorns/yolo` 时，路径操作会触发 `UnicornException`。

但该异常将会被 `unicorn_exception_handler` 处理。

你会收到清晰的错误信息，HTTP 状态码为 `418`，JSON 内容如下：

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}
```

/// note | 技术细节

也可以使用 `from starlette.requests import Request` 和 `from starlette.responses import JSONResponse`。

{* ../../docs_src/handling_errors/tutorial003_py310.py hl[5:7,13:18,24] *}

在這裡，如果你請求 `/unicorns/yolo`，該「路徑操作」會 `raise` 一個 `UnicornException`。

但它會被 `unicorn_exception_handler` 所處理。

因此你會得到一個乾淨的錯誤回應，HTTP 狀態碼為 `418`，JSON 內容如下：

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}
```

/// note | 技術細節

你也可以使用 `from starlette.requests import Request` 與 `from starlette.responses import JSONResponse`。