proxy_test.py

import urllib2

for line in open('proxy.txt','r').readlines(): 
    proxy = urllib2.ProxyHandler({'https': line})
    opener = urllib2.build_opener(proxy)
    urllib2.install_opener(opener)
    try:
        response = urllib2.urlopen('https://ctf.fluxfingers.net/ref/7xYpAcceEDfEEuk')
        datum = response.read().decode("UTF-8")
        response.close()
        print datum
        if 'Location' in datum:
            break
    except urllib2.URLError, e:
        print(str(e) + '\n')
        continue
    except Exception, e:
        print(str(e) + '\n')
        continue