class strest(tornado.web.RequestHandler):
    def post(self):
        value = self.get_argument('key')
        cbtp = cbt.main(value)

res = {cbtp: cbtp}
return cbtp

class strest(tornado.web.RequestHandler):
    def set_default_headers(self):
        self.set_header("Content-Type", 'application/json')

    def post(self):
        value = self.get_argument('key')
        cbtp = cbt.main(value)
        r = json.dumps({'cbtp': cbtp})
        self.write(r)