title: How to run Flask function that triggers on user's action and add content to the page?
body: <p>The idea is that user push the button and Flask should add some content on the page. <br/>
  In my case python and Flask <strong>is not</strong> an aleatory choice, because Python make a lot of backdoor work (that for example js can't). <br/>
  And perfectly it should be just one page without redirection on another page. <br/>
  So my question is: </p>
  
  <ol>
  <li>How to get the moment when user push the button and run the function I want</li>
  <li>How to make this function add some generated content on the page without reloading.</li>
  </ol>