python3访问sina首页中文的处理方法

"""
如果只用普通的
import urllib.request
html = urllib.request.urlopen("http://www.sina.com").read()
print(html.decode('gbk'))
出现下面的错误
builtins.UnicodeDecodeError: 'gbk' codec can't decode byte 0x8b in position 1: illegal multibyte sequence
怎么办？原来是有的网站将网页用gzip压缩了 。
请看下面的代码

import io
import urllib.request as r
import gzip
req = r.Request("http://www.sina.com", headers={"User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.63 Safari/537.36", "Accept-Encoding": "gzip"})
bs = r.urlopen(req).read()
bi = io.BytesIO(bs)
gf = gzip.GzipFile(fileobj=bi, mode="rb")
print(gf.read().decode("gbk"))