How to use Tornado coroutine in python2.7?

Error writing

class RemoteHandler(web.RequestHandler):

    @gen.coroutine
    def get(self):
        response = httpclient('http://www.baidu.com')
        self.write(response.body)

    @gen.coroutine
    def httpClient(url):
        result = yield httpclient.AsyncHTTPClient().fetch(url)
        return result

　

If you follow the general method of return, an error will be reported

You need to use raise gen.Return(response.body) instead of return

Official example

@gen.coroutine
def fetch_json(url):
    response = yield AsyncHTTPClient().fetch(url)
    raise gen.Return(json_decode(response.body))

　

In Python 3.3, this exception is no longer necessary: ​​the <span class="pre">return</span> statement can be used directly to return a value (previously <span class="pre">yield</span> and <span class="pre">return</span> with a value could not be combined in the same function).

In python 3.3 or above, there is no need to throw an exception and you can directly use return to return the value directly. In previous versions, yield and return with a return value could not be in the same function.

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