如下：
urllib.request.urlopen(url).info()的结果如下：
Content-Type: application/vnd.ms-excel
Connection: close
age: 942
CACHE: TCP_REFRESH_HIT
Vary: Accept-Encoding
Powered-By-ChinaCache: HIT from BGP-GZ-d-3WB
ETag: "160000000a84f5-7e00-574efad018534"
Last-Modified: Mon, 03 Sep 2018 04:07:12 GMT
Keep-Alive: timeout=60
Expires: Mon, 24 Sep 2018 13:39:59 GMT
Date: Mon, 24 Sep 2018 09:39:59 GMT
Content-Length: 32256
Server: ***
CC_CACHE: TCP_HIT
Accept-Ranges: bytes
requests.get(url, stream=True).headers 的结果如下：
{'Content-Type': 'application/vnd.ms-excel', 'Connection': 'keep-alive', 'age': '941', 'CACHE': 'TCP_HIT', 'Date': 'Mon, 24 Sep 2018 09:40:00 GMT', 'Powered-By-ChinaCache': 'HIT from BGP-GZ-d-3WB', 'ETag': '"160000000a84f5-7e00-574efad018534"', 'Expires': 'Mon, 24 Sep 2018 13:40:00 GMT', 'Keep-Alive': 'timeout=60', 'Vary': 'Accept-Encoding', 'Content-Length': '12492', 'Content-Encoding': 'gzip', 'Last-Modified': 'Mon, 03 Sep 2018 04:07:12 GMT', 'Server': '***', 'CC_CACHE': 'TCP_HIT', 'Accept-Ranges': 'bytes'}
区别：
urllib:
Content-Length: 32256
requests:
'Content-Length': '12492'
'Content-Encoding': 'gzip',
如果不使用gzip可以这么提交：
headers1 = {'Accept-Encoding': ''} # ,headers=headers1
data = requests.get(url, stream=True,headers=headers1).headers