code: def send_file(self, file):
          
          if self.logger:
              self.logger.debug("[ioc.extra.tornado.RouterHandler] send file %s" % file)
  
          self.send_file_header(file)
  
          fp = open(file, 'rb')
          self.write(fp.read())
  
          fp.close()
docs: Send a file to the client, it is a convenient method to avoid duplicated code