title: shutil.get_terminal_size() does not change
body: <p>I am using curses to print a pretty nice console UI, and I need for that something to be dependent of the terminal size. For this, I read <a href="https://stackoverflow.com/questions/566746/how-to-get-linux-console-window-width-in-python">here</a>, that I could use <code>shutil.get_terminal_size</code>.
  So I'm doing this code : </p>
  
  <pre><code>def display(self):
      size_x,size_y = shutil.get_terminal_size()
      print(size_x,size_y)
      window_stat = curses.newwin(size_y,size_x//2-5,0,0)
      window_alert = curses.newwin(size_y,size_x//2-5,0,size_x//2+5)
      window_alert.addstr("\n   " + self.alert2string())
      window_stat.addstr("\n   " + self.stat2string())
      window_alert.box()
      window_stat.box()
      self.stdscr.refresh()
      window_stat.refresh()
      window_alert.refresh()
  </code></pre>
  
  <p>But the fast is that, it is working perfectly the first time I call the function, but if I use my mouse to change the terminal size and recall the function, the result of <code>shutil.get_terminal_size()</code> will always stay the same. (120 30).</p>
  
  <p>Do you have any idea of where it could come from ? 
  (I'm running Windows actually, and I'd like it to work under all common OS)</p>
  
  <p>Thanks a lot everyone ! </p>