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

[Terry Reedy]

On 4/1/2014 5:26 PM, Mark H Harris wrote:

>>>>>  I didn't really start using unicode
>>>>> until about 5 years ago; python has only really used it since python3.
>>>>> right?

If you narrowly meant "The python interpreter only starting using 
unicode as the default text class in 3.0", then you are, in that narrow 
sense, correct. If you meant something broader, if by 'python' you meant 
'the python community' or 'python programmers', then you are wrong.

>>>>  No. Python 2.2 introduced Unicode.

2.0, as someone else corrected.

>>>  I didn't ask when it was introduced, I asked when it became useful?

It was useful immediately when introduced. Do you really think we would 
add something useless, and that no one wanted to use?  Core developers 
constantly ask 'What is the practical use case?' in response to 
suggested additions.

For either question, your original answer is wrong.

>> No you didn't.

Does not matter. The answer he gave to the question he claims he asked, 
and the elaboration below, is wrong.

>     Yes, I did.

Fine. You asked 'When did unicode in Python become useful.'
Answer: 2.0, not 3.0. Most unicode use in Python is still running on 
Python 2. It works well enough that people are reluctant to migrate 
working and tested production code. End of discussion?

 > Our common English is apparently getting in the way.
> Well, I speak American English, and you don't, apparently; U.K.?

I hear, speak, read, and write standard American English.

-- 
Terry Jan Reedy