tornado通过发送二进制流给前端，显示图片

#coding:utf-8
import tornado.ioloop
import tornado.web
from  tornado.options import define,options,parse_command_line
from tornado.web import RequestHandler


define('port',default=8001,type=int,)
def main():
    parse_command_line()
    app=tornado.web.Application(
        [
        (r"/pic/*.*",PicHandles),
],
   debug=True,
   default_host="0.0.0.0",
)
    app.listen(options.port)
    tornado.ioloop.IOLoop.instance().start()

class PicHandles(RequestHandler):
    def get(self):
        data={}
        data['pic_id']=self.request.uri.split('/')[-1:][0]
        if int(data['pic_id'])==2:
          pic=open('/home/wang/Desktop/canpin/1.jpg','r')
          pics=pic.read()
          self.write(pics)
          self.set_header("Content-type", "p_w_picpath/png")
        else:
            self.write('no url')
if __name__=='__main__':
    main()