How to send simulated keyboard strokes to the active window using SendKeys

Question

I am new to Python and am trying to send a combination of key strokes to an application I open under Windows 7. While my script will work flawlessly when I invoke Notepad.ex

Answer 1

OK ... I rebooted the system and for some reason it is working now. I am wondering if some process instance from previous programme invocations might have been lingering on the system. Anyway, I am now able to perform the manipulations as expected, even if I don't really understand what went wrong in the first place.

Thanks to everyone who took the time to repsond.