判断URL是否支持断点续传？

#python
#xiaodeng
#判断URL是否支持断点续传？

import urllib2  

req = urllib2.Request('http://ftp.ubuntu.com/')
req.add_header('Range', 'bytes=0-20')
res = urllib2.urlopen(req)  

print res.headers
print res.headers['Content-Type']#text/html;charset=UTF-8

#判断该URL是否支持断点续传？
#首先由长度，其次有Range便支持断点续传～～
print res.headers['Content-Length']#
print res.headers['Content-Range']#bytes 0-20/592

'''
Date: Mon, 02 Nov 2015 10:20:42 GMT
Server: Apache
Vary: Accept-Encoding
Content-Range: bytes 0-20/592
Content-Length: 21
Connection: close
Content-Type: text/html;charset=UTF-8

'''