Determine proxy type

Question

I have the following code to download a URL through a proxy:

proxy_handler = urllib2.ProxyHandler({'http': p})
opener = urllib2.build_opener(proxy_handler)
urllib2.install_opener(opener)
req = urllib2.Request(url)
sock = urllib2.urlopen(req)

How can I use Python to determine the type of proxy it is (transparent, anonymous, etc)? One solution would be to use an external server, but I want to avoid that kind of dependency if possible.

Answer 1

One solution would be to use an external server

You must have a server of some sort.

The best option you can hope of doing is to host your own web server and print the headers to see if it is leaking any variables.