python aiohttp download pictures

I use asyncio to download pictures. I can download them but cannot open them

@asyncio.coroutine # <3>
def get_flag(cc):

print(6)
resp = yield from aiohttp.request('GET', cc)  # <4>
image = yield from resp.read()  # <5>
##########有问题
return image
//////////////////////////////////////
上边是代码，能够request，但是在read的时候就出现问题了，cc是图片的路径