How to detect mouse and keyboard inactivity in linux

I am developing an app on 开发者_JAVA技巧python which will check for user inactivity. Is there a way to check for key press and mouse move events in linux?

You could monitor the /dev/input/* files, when a key is pressed/the mouse is moved it is written to one of those files.

Try this for example:

fh = file('/dev/input/mice')
while True:                 
    fh.read(3)
    print 'Mouse moved!'

Now that I think of it, it might be better to use something like xidle to detect inactivity.