I am writing a small tkinter-app involving user keyboard-input, and want to control the range of acceptable input-characters. I'm currently using an Entry-widget, but haven't been able to access the individual characters AS THEY ARE ENTERED. What I (think I:confused:) need is somthing like the 'command=' option (as in the Button-widget), which would call a function at each keyboard-entry. Can anyone point me in the right direction? Thanks.