title: How run a python script one line by one line (pause after every line)?
body: <p>I have seen someone using such a module in a video course or something. However, I googled and found nothing.</p>
  
  <p>As I can remember, a module is imported at the beginning of the script. When running, the script is paused after every line, and the result is shown. This module is great for presentation.</p>