Explanation of this Python language feature? [x for x in x for x in x] (to flatten a nested list)

[Mark H Harris]

On 3/28/14 11:07 PM, Mark H Harris wrote:
> Think, virtual keyboard, on a keytoplayout... but separate from any
> touchable screen. And, think mac keytops (or flatter) not the plastic
> IBM typewriter like keyboards of today. Think beyond.

What if~  when I select my UK standard keytop mappings (from my US 
custom keytop mappings) what if the actual keytops on the keyboard 
"morphed" into UK tops?

Better yes, what if the whole keytopsection could morph into Greek tops?

I am able to type in Greek, well I've been doing it for about 12 years, 
but it would be soooo much better if the keytopsection actually morphed.

marcus