使用tornado.httpclient.AsyncHTTPClient時，如何修復“RuntimeWarning：啟用tracemalloc以獲取對象分配回溯”？

Question

我用tornado.httpclient.AsyncHTTPClient在我的龍卷風Web應用程序” headler。

這是我的代碼

class CustomTornadoHandler(tornado.web.RequestHandler):

    def set_default_headers(self):
        self.set_header("Access-Control-Allow-Origin", "*")
        self.set_header("Access-Control-Allow-Headers", "x-requested-with,application/x-www-form-urlencoded")
        self.set_header('Access-Control-Allow-Methods', 'POST, GET, OPTIONS, PATCH, DELETE, PUT')

    def initialize(self, *args, **kwargs):
        self.db_session = db_session()

    def on_finish(self):
        db_session.remove()


class AdminUploadAlignerParagraphTaskHandler(CustomTornadoHandler):

    executor = concurrent.futures.ThreadPoolExecutor()

    @run_on_executor
    def post(self):

        async def f():
            http_client = tornado.httpclient.AsyncHTTPClient()
            try:
                response = await http_client.fetch("http://www.google.com")
            except Exception as e:
                print("Error: %s" % e)
            else:
                logging.info(response.body)
        ...
        self.write("")
        f()

我在https://www.tornadoweb.org/en/stable/httpclient.html中獲得了示例。 但它不起作用：

RuntimeWarning: coroutine 'AdminUploadAlignerParagraphTaskHandler.post.<locals>.f' was never awaited
  f()
RuntimeWarning: Enable tracemalloc to get the object allocation traceback

我該怎么辦？

Answer 1

函數f()是一個協程，你只是在沒有等待的情況下調用它。 你需要使用await f()來調用它。 要實現這一點，您還需要將post方法轉換為協程。

---

你不必要地使post方法復雜化。 我不明白你為什么要在一個單獨的線程上運行它。

這是我如何重寫它：

# no need to run on separate thread
async def post():
    http_client = tornado.httpclient.AsyncHTTPClient()

    try:
        response = await http_client.fetch("http://www.google.com")
    except Exception as e:
        print("Error: %s" % e)
    else:
        logging.info(response.body)

    ...

    self.write("")