Python aiohttp后台导出excel文件

import xlwt
from io import StringIO,BytesIO

@get('/channel/download')

def manage_download_channels():
    workbook = xlwt.Workbook(encoding = 'utf8')
    worksheet = workbook.add_sheet('渠道明细')
    worksheet.write(0,0, '渠道编码')
    worksheet.write(0,1, '渠道名称')
    sio = BytesIO()
    workbook.save(sio)
    r = web.Response()
    r.content_type = 'application/vnd.ms-excel'
    r.body=sio.getvalue()
    return r