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

[Mark H Harris]

On 3/27/14 7:34 PM, Steven D'Aprano wrote:
 > As for enormous number of users who will have
 > difficulty typing √ in their source code, they certainly don't count!
 > It's good enough that *you* have a solution to that problem, you can type
 > alt-v, and anyone who can't simply doesn't matter.

You have an interesting point here; more interesting perhaps than you know.

We have a unicode system [1] capable of zillions of characters, and most 
of [us] have some qwerty system keyboard [104 keys?] with meta key 
mappings for a few more. Talk about the cart before the horse.

We need a standard input system not controlled by Microsoft where-by 
everyone in the entire world can enter unicode (with customization) 
easily and inexpensively. A unicode keyboard would be nice. Why must 
everyone in the world be stuck with a U.S. Royal typewriter keyboard for 
two or three hundred years? Dvorak had the right idea; but it didn't 
stick (although I have a Dvorak key mapping I use (with emacs) just for 
fun).

I do care, Steven. You'll never ever hear me say "screw" somebody, not 
because I'm holier than thou, but because everyone counts--everyone.

Your point about the biologist is fabulous (my point as well), "I didn't 
study biology for six years to wash test tubes and program computers, 
but it comes with the territory".  Steven, dude, you proved my point 
with that. Most biologists (academics particularly) are studying systems 
that require computers these days--- and the scientists in that field DO 
want to program computers (I didn't say love) and the "want" is 
powerful.  I didn't say that they "liked it" either. Somehow a biologist 
needs to be able to talk to that goofy machine (which they hate) and be 
able to do so efficiently and I dare say rapidly. There needs to be a 
system for them; general, easy, elegant yet comprehensible, flexible yet 
unified, discrete, simplified (without being oversimplified).  wow. Talk 
development requirements.

marcus


[1]  http://www.unicode.org/standard/where/