from fastapi import FastAPI, HTTPException

app = FastAPI()

items = {"foo": "The Foo Wrestlers"}


@app.get("/items-header/{item_id}")
async def read_item_header(item_id: str):
    if item_id not in items:
        raise HTTPException(
            status_code=404,
            detail="Item not found",
            headers={"X-Error": "There goes my error"},
        )

    all_good = True
    for page in docs:
        doc_path = Path("docs") / language / "docs" / page
        res = process_one_page(doc_path)
        all_good = all_good and res

    if not all_good:
        raise typer.Exit(code=1)


@cli.command()
def fix_pages(
    doc_paths: Annotated[
        list[Path],
        typer.Argument(help="List of paths to documents."),
    ],
):
    all_good = True

        logging.error(response.text)
        raise RuntimeError(response.text)
    data = response.json()
    if "errors" in data:
        logging.error(f"Errors in response, after: {after}")
        logging.error(data["errors"])
        logging.error(response.text)
        raise RuntimeError(response.text)
    return data


def get_graphql_sponsor_edges(

### 在代码中触发 `HTTPException` { #raise-an-httpexception-in-your-code }

`HTTPException` 是额外包含了和 API 有关数据的常规 Python 异常。

因为是 Python 异常，所以不能 `return`，只能 `raise`。

这也意味着，如果你在*路径操作函数*里调用的某个工具函数内部触发了 `HTTPException`，那么*路径操作函数*中后续的代码将不会继续执行，请求会立刻终止，并把 `HTTPException` 的 HTTP 错误发送给客户端。

在介绍依赖项与安全的章节中，你可以更直观地看到用 `raise` 异常代替 `return` 值的优势。

本例中，客户端用不存在的 `ID` 请求 `item` 时，触发状态码为 `404` 的异常：

        message = 'To use the fastapi command, please install "fastapi[standard]":\n\n\tpip install "fastapi[standard]"\n'
        print(message)
        raise RuntimeError(message)  # noqa: B904

            except RequestValidationError as exc:
                body = await request.body()
                detail = {"errors": exc.errors(), "body": body.decode()}
                raise HTTPException(status_code=422, detail=detail)

        return custom_route_handler


app = FastAPI()
app.router.route_class = ValidationErrorLoggingRoute


@app.post("/")

FastAPI 0.110.0 öncesinde, `yield` kullanan bir dependency kullanır, sonra o dependency içinde `except` ile bir exception yakalar ve exception'ı tekrar raise etmezseniz; exception otomatik olarak herhangi bir exception handler'a veya internal server error handler'a raise/forward edilirdi.

        message += f"\nField: {error['loc']}, Error: {error['msg']}"
    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.")

    print(f"OMG! The client sent invalid data!: {exc}")
    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.")

        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)