How to tell if a key has been released in tkinter

Question

I am using this code to test whether a key has been pressed, but I also need a binding that is called when a key is released. If no such binding exists, I would settle for a

Answer 1

This will call onkeyrelease when any key is released:

w.bind("<KeyRelease>", onkeyrelease)

To react to a particular key's release, you would use

w.bind("<KeyRelease-key>", onkeyrelease_of_key)

where key should be replaced by the name of the key.