except InternalError:
        print("Oops, we didn't raise again, Britney 😱")


@app.get("/items/{item_id}")
def get_item(item_id: str, username: str = Depends(get_username)):
    if item_id == "portal-gun":
        raise InternalError(
            f"The portal gun is too dangerous to be owned by {username}"
        )
    if item_id != "plumbus":
        raise HTTPException(

    except InternalError:
        print("Oops, we didn't raise again, Britney 😱")


@app.get("/items/{item_id}")
def get_item(item_id: str, username: Annotated[str, Depends(get_username)]):
    if item_id == "portal-gun":
        raise InternalError(
            f"The portal gun is too dangerous to be owned by {username}"
        )
    if item_id != "plumbus":
        raise HTTPException(

        yield "Rick"
    except OwnerError as e:
        raise HTTPException(status_code=400, detail=f"Owner error: {e}")


@app.get("/items/{item_id}")
def get_item(item_id: str, username: str = Depends(get_username)):
    if item_id not in data:
        raise HTTPException(status_code=404, detail="Item not found")
    item = data[item_id]
    if item["owner"] != username:
        raise OwnerError(username)

{* ../../docs_src/handling_errors/tutorial001_py310.py hl[1] *}

### 在程式中 raise 一個 `HTTPException` { #raise-an-httpexception-in-your-code }

`HTTPException` 是一般的 Python 例外，但包含與 API 相關的附加資料。

因為它是 Python 的例外，你不是 `return`，而是 `raise`。

這也表示，如果你在某個工具函式中（該函式被你的「路徑操作函式」呼叫），並在該工具函式裡 raise `HTTPException`，那麼「路徑操作函式」剩下的程式碼將不會執行；該請求會立刻被終止，並將 `HTTPException` 的 HTTP 錯誤傳回給用戶端。

為何選擇 raise 例外而非回傳值的好處，會在相依性與安全性章節更為明顯。

    Note over client,operation: Can raise exceptions, including HTTPException
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise Exception
        dep -->> handler: Raise Exception
        handler -->> client: HTTP error response
    end
    dep ->> operation: Run dependency, e.g. DB session
    opt raise
        operation -->> dep: Raise Exception (e.g. HTTPException)
        opt handle

    Note over client,operation: Can raise exceptions, including HTTPException
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise Exception
        dep -->> handler: Raise Exception
        handler -->> client: HTTP error response
    end
    dep ->> operation: Run dependency, e.g. DB session
    opt raise
        operation -->> dep: Raise Exception (e.g. HTTPException)
        opt handle

        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        token_data = TokenData(username=username)
    except InvalidTokenError:
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    return user


async def get_current_active_user(

            if self.auto_error:
                raise self.make_not_authenticated_error()
            else:
                return None
        try:
            data = b64decode(param).decode("ascii")
        except (ValueError, UnicodeDecodeError, binascii.Error) as e:
            raise self.make_not_authenticated_error() from e
        username, separator, password = data.partition(":")

    hero = session.get(Hero, hero_id)
    if not hero:
        raise HTTPException(status_code=404, detail="Hero not found")
    return hero


@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(hero_id: int, hero: HeroUpdate, session: SessionDep):
    hero_db = session.get(Hero, hero_id)
    if not hero_db:
        raise HTTPException(status_code=404, detail="Hero not found")

	user := User{Name: "transaction"}
	if err := tx.Save(&user).Error; err != nil {
		t.Fatalf("No error should raise")
	}

	if err := tx.Commit().Error; err != nil {
		t.Fatalf("Commit should not raise error")
	}

	if err := tx.Rollback().Error; err == nil {
		t.Fatalf("Rollback after commit should raise error")
	}
}

func TestTransactionWithSavePoint(t *testing.T) {
	tx := DB.Begin()