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

[Mark H Harris]

On 4/4/14 7:00 PM, Steven D'Aprano wrote:
>
> Berp, Brython, CLPython, CPython, CapPython, ChinesePython, Compyler,
> Copperhead, Cython, HoPe, HotPy, IronPython, Jython, Kivy, Mypy, Mython,
> Nuitka, Numba, Parakeet, Parallel Python, Perthon, Pippy, Psyco, Py4A,
> PyMite, PyMT, PyPad, PyPy, PyQNX, PyVM, Pycorn, Pyjamas, Pynie,
> Pystachio, Pyston, Python for .NET, Python for OS/2, Python for S60,
> Python-iPod, Python2C, Pythonce, Pythonium Core, Pythran, QPython,
> RapydScript, Shedskin, Skulpt, Stackless, TinyPy, Typhon, UnPython,
> Unladen Swallow, Vyper, WPython

    Thanks for this list.
>
> As I said, some of these may be abandoned, obsolete, experimental, or
> even vapourware. Some are probably just ports of CPython to another
> platform rather than completely independent implementations.

    The only one I've used regularly is QPython (on Android) which is 
apparently a 2.7.2 port. Its relatively slow but 'useful' because its 
obviously highly mobile, which gives me the opportunity to 
code-on-the-go, or try a new idea in those awkward times when only a 
cell-phone is convenient for the venue.

>> but I know that Jython and IronPython are
>> serious contenders (although, I have not, nor probably will, use them).
>
> If you are using a Debian-based system, it is trivial to install them via
> apt-get or aptitude:
>
>      sudo aptitude install jython ironpython

    Its has always seemed to me that Java or C++ would be better suited 
to creating python. I wonder will C always be the standard canonical PSF 
python interpreter base language? Has the C python community considered 
making the standard base language Java or C++ ?


marcus