make_app(): return tornado.web.Application([ (r"/", MainHandler), ]) async def main(): app = make_app() app.listen(8888) await asyncio.Event().wait() if __name__ == "__main__": asyncio.run(main()) components like the IOLoop that use callbacks. Futures are usually transformed into their result with the await or yield keywords. Examples Here is a sample synchronous function: from tornado.httpclient import coroutine: from tornado.httpclient import AsyncHTTPClient async def asynchronous_fetch(url): http_client = AsyncHTTPClient() response = await http_client.fetch(url) return response.body Or for compatibility

return tornado.web.Application([ (r"/", MainHandler), ]) async def main(): app = make_app() app.listen(8888) await asyncio.Event().wait()if __name__ == "__main__": asyncio.run(main()) components like the IOLoop that use callbacks. Futures are usually transformed into their result with the await or yield keywords. Examples Here is a sample synchronous function: from tornado.httpclient import coroutine: from tornado.httpclient import AsyncHTTPClient async def asynchronous_fetch(url): http_client = AsyncHTTPClient() response = await http_client.fetch(url) return response.body Or for

373 17. Async 和 await . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375 17.1. Futures 和 async 语法 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378 17.2. 并发与 async . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 17.5. 深入理解 async 相关的 traits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .