title: Proxy Check in python
body: <p>I have written a script in python that uses cookies and POST/GET. I also included proxy support in my script. However, when one enters a dead proxy, the script crashes. Is there any way to check if a proxy is dead/alive before running the rest of my script?</p>
  <p>Furthermore, I noticed that some proxies don't handle cookies/POST headers properly. Is there any way to fix this?</p>