title: Python prevent multiple-instances / tkinter instance
body: <p>Python 3.10 (OS Windows 10, 64 bit)</p>
  <p>Hi,</p>
  <p>I compiled my Python tkinter code. When
  I run the *.exe twice there are two tkinter main
  windows (the same as when I'd
  run the windows notepad.exe twice).</p>
  <p>But I want to prevent the tkinter .exe can be
  started twice. Can I do something so that tkinter
  can be started only one time no matter
  whether I click tkinter.exe on the
  windows desktop a dozen times .</p>