title: How to select a form with xpath in Mechanize/Python?
body: <p>I am visiting a stateful web service with mechanize/Python. It confirm the referrer of a request and my browser's cookie.
  Since most forms of the site don't have name attribute, I'm tired to select forms.</p>
  
  <p>I would like to use xpath like <code>//*[@id="top"]/div[3]/form/input[@type="submit"]</code> and submit it.
  Do you have any ideas to select forms with xpath?</p>