[Python-3000] PEP 3131 accepted

[Stephen J. Turnbull]

Guido van Rossum writes:
 > We should probably be conservative; I'm not too hopeful about
 > support for right-to-left alphabets for example.

I don't see what's for *Python* to *support*.  

My reasoning: bidi is entirely an issue of presentation; all Python
should do is prohibit[1] direction markers in identifiers.  To the
extent that we don't know of editors that can consistently[2] present
such identifiers as users would expect to see them, say bidi
identifiers should be avoided as a "best current practice".

AFAICS, PEP 3131 is going to work fine if we just delegate all the
problems that have been brought up to the development environment in
that way, except the important issues that Ka-Ping raises.  IMHO the
answer you gave is entirely satisfactory.


Footnotes: 
[1]   Or ignore, but I prefer prohibit because the bookkeeping
involved in ensuring that introspective output produces the identifier
that was read in from a file is unjustifiable overhead, and because
permitting them opens the door to "stupid bidi tricks" by authors (we
can't do anything about people who let their editors play stupid bidi
tricks on them).

[2]  Ie, so that different identifiers always look different, and the
same identifier is always presented in the same form.