龙卷风:异步端点

Question

我有以下代码：

class StackOverflowHandler(tornado.web.RequestHandler):
    def get(self, look_up_pattern):
        url = "https://api.stackexchange.com/2.2/search?order=desc&sort=votes&intitle=%s&site=stackoverflow"
        response = self.async_get(url)
        print(response)
        self.write(response)
    @gen.coroutine
    def async_get(self, url):
        link = httpclient.AsyncHTTPClient()
        request = httpclient.HTTPRequest(url)
        response = yield link.fetch(request)
        data = response.body.decode('utf-8')
        data = json.loads(data)
        return data
application = tornado.web.Application([
    (r"/search/(.*)", StackOverflowHandler),
])

从async_get返回的类型是 tornado.concurrent.Future 。

例外情况是：

TypeError: write() only accepts bytes, unicode, and dict objects

我是异步编程的新手，请指出我的错误。

Answer 1

由于async_get是协程，因此它返回Future对象。为了获得"真正的"结果，必须解决未来问题——它需要产生。此外，get处理程序也必须装饰为异步

class StackOverflowHandler(tornado.web.RequestHandler):
    @gen.coroutine
    def get(self, look_up_pattern):
        url = "https://api.stackexchange.com/2.2/search?order=desc&sort=votes&intitle=%s&site=stackoverflow"
        response = yield self.async_get(url)
        print(response)
        self.write(response)
    @gen.coroutine
    def async_get(self, url):
        link = httpclient.AsyncHTTPClient()
        request = httpclient.HTTPRequest(url)
        response = yield link.fetch(request)
        data = response.body.decode('utf-8')
        data = json.loads(data)
        return data