Search code examples
pythonasynchronouswebtornado

using gen.task with Tornado for a simple function


Just trying to use the async functions of Tornado - I want to invoke a method from my handler but it keeps telling me that it "got an unexpected keyword argument 'callback'".

class MyHandler(tornado.web.RequestHandler):

    @asynchronous
    @gen.engine
    def get(self):
        response = yield gen.Task(self.dosomething, 'argument')
        self.write(response)
        self.finish()

    def dosomething(self, myargument):
        pass

Solution

  • Non-blocking function requires callback, where it pass result.

    class MyHandler(tornado.web.RequestHandler):
    
        @asynchronous
        @gen.engine
        def get(self):
            response = yield gen.Task(self.dosomething, 'argument')
            self.write(response)
            self.finish()
    
        def dosomething(self, myargument, callback):
            return callback(myargument)