title: Python issue with CTRL-V in Tkinter Entry widget
body: <p>In the Entry widget, I tried to restrict values to only hexadecimal using <code>validatecommand</code> and a function to verify if the entry value is in 'abcdef0123456789'. The problem lies in the fact that "CTRL+V" (Paste) doesn't work when I use it to insert value. There is no problem with "CTRL+C" and "CTRL+X" (Copy and Cut).</p>
  
  <p>Is that a way to restrict the entry to hexadecimal value and in same time allow the use of CTRL-V to Paste/insert value? </p>