python urllib2: connection reset by peer

Question

I have a perl program that retrieves data from the database of my university library and it works well. Now I want to rewrite it in python but encounter the problem <urlopen error [errno 104] connection reset by peer>

The perl code is:

    my $ua = LWP::UserAgent->new;
    $ua->cookie_jar( HTTP::Cookies->new() );
    $ua->timeout(30);
    $ua->env_proxy;
    my $response = $ua->get($url); 

The python code I wrote is:

    cj = CookieJar();
    request = urllib2.Request(url); # url: target web page 
    opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj));
    opener = urllib2.install_opener(opener);
    data = urllib2.urlopen(request); 

I use VPN(virtual private network) to log in my university's library at home, and I tried both the perl code and python code. The perl code works as I expected, but the python code always encountered "urlopen error".

I googled for the problem and it seems that the urllib2 fails to load the environmental proxy. But according to the document of urllib2, the urlopen() function works transparently with proxies which do not require authentication. Now I feels quite confusing. Can anybody help me with this problem?

Answer 1

I tried faking the User-Agent headers as Uku Loskit and Mikko Ohtamaa suggested, and solved my problem. The code is as follows:

    proxy = "YOUR_PROXY_GOES_HERE"
    proxies = {"http":"http://%s" % proxy}
    headers={'User-agent' : 'Mozilla/5.0'}
    proxy_support = urllib2.ProxyHandler(proxies)
    opener = urllib2.build_opener(proxy_support, urllib2.HTTPHandler(debuglevel=1))
    urllib2.install_opener(opener)

    req = urllib2.Request(url, None, headers)
    html = urllib2.urlopen(req).read()
    print html

Hope it is useful for someone else!