title: Taking a screenshot of a web page in PyQt5
body: <p>I would like to use PyQt5 to take a screenshot of a webpage. (A full webpage, including the stuff a user wouldn't see unless they scrolled down.)</p>
  
  <p><a href="https://stackoverflow.com/questions/29547460/render-web-content-offscreen-using-qtwebengine">Supposedly, it is possible to do this in PyQt5 using QtWebEngine</a>. How would you do it though? I specifically don't want the user to see a browser window opening or rendering. I just want a screenshot in a PNG file.</p>