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

[Chris Angelico]

On Sat, Apr 5, 2014 at 4:29 PM, Ben Finney <ben+python at benfinney.id.au> wrote:
> Chris Angelico <rosuav at gmail.com> writes:
>
>> I would suggest that the more prolific posters are going to be those
>> who use Python more (and thus it's worth investing more time in),
>> which is going to skew the post stats towards the professional end of
>> the spectrum.
>
> It's also plausible that the more prolific posters are those who spend
> *less* time actually coding, and instead spend their free time being
> prolific in this forum.

Heh. Very true.

> Other explanations are plausible. Any of them could be contributing
> factors in any mixture.
>
> Without actual data – which neither of us has on this matter – all of
> these hypotheses are unfounded speculation. Let's not draw any
> conclusions in the absence of evidence.

Not to mention that there's not a lot of difference between an
unemployed professional coder and a serious hobbyist. :)

ChrisA