keyboard.py example not working

Thanks for this excellent question!

Yes, this is a known "feature" and it has actually nothing to do with uinput nor python-uinput. The reason why you don't see any output when examples/keyboard.py is run is due to delays in the underlying infrastructure (=xorg + its mechanisms to assign handlers for input devices).

I think the whole process chain goes like this:
1. user runs examples/keyboard.py
2. examples/keyboard.py uses kernel's uinput-interface to create a device
3. xorg receives a notification that there is a new keyboard device available and starts assigning a handler for the device (ASYNCHRONOUS)
4. examples/keyboard.py emits keyboard events via uinput-interface
5. examples/keyboard.py has done its job, the device is removed and examples/keyboard.py exits

The keyword here is of course 'asynchronous'. examples/keyboard.py lives its own life and does not care about Xorg at all. Xorg (or any other UI manager) does its processing and input device handling asynchronously in the background. It seems that there isn't any buffering going on, and therefore all events emitted before Xorg has assigned a proper handler are lost.

Try adding a small delay after the device initialization as follows:

  device = uinput.Device(events)
  time.sleep(2) # seconds

And the "problem" should disappear. However, note that in any real application should not be a problem, since in most cases there is already a natural delay (caused by user actions or cpu processing) between the device initialization and event emitting.