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

[Chris Angelico]

On Sat, Mar 29, 2014 at 4:51 PM, Mark H Harris <harrismh777 at gmail.com> wrote:
> On 3/29/14 12:08 AM, Chris Angelico wrote:
>
>>
>> Okay. History lesson time.
>>
>
>    Tell me what is the lingua franka today?
>
>    Is it,   E n g l i s h ?
>
>    For many many many years people all over the earth were using English and
> ASCII to communicate with early computers... they still are. Almost every
> post on every site is English, and nearly every post on every site is a
> Latin character derivative.

http://forum.ecomstation.ru/

Prominent discussion forum, although that strives to be at least
partially bilingual in deference to those of us who are so backward as
to speak only English.

>    Kanji and Cyrillic , and Arabic are obvious exceptions to that today,
> mostly because of unicode; NOT extend ASCII.
>
>> Back before I was born, people were using computers to write messages
>> that weren't in English.
>
>
>    No, they weren't... not most... some.

So, pre-Unicode, people didn't use any of those languages or writing
systems with computers, is that what you're saying? That code pages
86x are a total myth?

>> And they managed it, somehow. Can't imagine
>> how, if all computers work exclusively with seven-bit Latin-derived
>> character sets.
>
>
>    Unicode. Shoot, most of the world didn't even have computers until just a
> few years ago; none of the third world did, back in the day, and the ones
> who did communicated in ASCII and English (or some broken variant of it).

Unicode didn't even begin to exist until 1987, and the first version
of the standard wasn't published until 1991. You're seriously saying
that until 1991 (plus however long it took to get implementations into
people's hands) everyone spoke English with computers?!?

>> "Most non-third-world countries use Latin-derived character sets".
>
>
>    See this quote from the consortium FAQ:
>
>    >  So, for example, there is only one set of Latin characters
>    > defined, despite the fact that the Latin script
>    > is used for the alphabets of thousands of different languages.
>
> http://www.unicode.org/faq/basic_q.html#3

Huh?


I'm not sure whether you're trolling or genuinely ignorant of all
history and other languages. Please clarify. If you really are just
trolling, say so, and I'll start ignoring all your posts. You'll make
yourself look less of a fool that way.

ChrisA