"portal-gun": {"description": "Gun to create portals", "owner": "Rick"},
}


class OwnerError(Exception):
    pass


def get_username():
    try:
        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: Annotated[str, Depends(get_username)]):

/// info

我们将`SessionLocal()`请求的创建和处理放在一个`try`块中。

然后我们在finally块中关闭它。

通过这种方式，我们确保数据库会话在请求后始终关闭。即使在处理请求时出现异常。

但是您不能从退出代码中引发另一个异常（在yield之后）。可以查阅 [Dependencies with yield and HTTPException](https://fastapi.tiangolo.com/zh/tutorial/dependencies/dependencies-with-yield/#dependencies-with-yield-and-httpexception)

///

*然后，当在路径操作函数*中使用依赖项时，我们使用`Session`，直接从 SQLAlchemy 导入的类型声明它。

    }
    val result = plans[nextPlanIndex++]
    events += "take plan ${result.id}"

    if (result.yieldBeforePlanReturns) {
      taskFaker.yield()
    }

    val planningThrowable = result.planningThrowable
    if (planningThrowable != null) throw planningThrowable

    return result
  }

from fastapi.testclient import TestClient


@pytest.fixture(name="app", scope="module")
def get_app():
    with pytest.warns(DeprecationWarning):
        from docs_src.events.tutorial002 import app
    yield app


def test_events(app: FastAPI):
    with TestClient(app) as client:
        response = client.get("/items/")
        assert response.status_code == 200, response.text

    return x * 42


ml_models = {}


@asynccontextmanager
async def lifespan(app: FastAPI):
    # Load the ML model
    ml_models["answer_to_everything"] = fake_answer_to_everything_ml_model
    yield
    # Clean up the ML models and release the resources
    ml_models.clear()


app = FastAPI(lifespan=lifespan)


@app.get("/predict")
async def predict(x: float):

from fastapi import Depends, FastAPI, HTTPException

app = FastAPI()


class InternalError(Exception):
    pass


def get_username():
    try:
        yield "Rick"
    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(

from fastapi import FastAPI
from fastapi.responses import StreamingResponse

app = FastAPI()


async def fake_video_streamer():
    for i in range(10):
        yield b"some fake video bytes"


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

from typing import Annotated

from fastapi import Depends, FastAPI, HTTPException

app = FastAPI()


class InternalError(Exception):
    pass


def get_username():
    try:
        yield "Rick"
    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":

from typing import Annotated

from fastapi import Depends, FastAPI, HTTPException

app = FastAPI()


class InternalError(Exception):
    pass


def get_username():
    try:
        yield "Rick"
    except InternalError:
        print("We don't swallow the internal error here, we raise again 😎")
        raise


@app.get("/items/{item_id}")
def get_item(item_id: str, username: Annotated[str, Depends(get_username)]):

                interruptee.interrupt();
                Thread.yield();
              }
            }
          });
      this.shutdown = shutdown;
      start();
    }

    @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
    void shutdown() {
      shutdown.set(true);
      while (this.isAlive()) {
        Thread.yield();
      }
    }
  }