[Python-3000] Support for PEP 3131

["Martin v. Löwis"]

>> > Python currently provides to everyone the restriction of
>> > identifiers to a character set that everyone knows and trusts.
>> > Many of us want Python to continue to provide such restriction
>> > for those who want identifiers to be in a character set they
>> > know and trust.  This is not incompatible with your desire to
>> > permit alternative character sets, as long as Python offers an
>> > option to make that choice.  We can continue to discuss the
>> > details of how that choice is expressed, but this general idea
>> > is a solution that would give us both what we want.
>> >
>> > Can we agree on that?
>>
>> So far, all proposals I have seen *are* incompatible, or had
>> some other flaws, so I'm not certain that this general idea
>> provides a non-empty solution set.
> 
> python -ascii-only

That doesn't implement the requirement "restriction for those
who want identifiers to be in a character set they know and
trust", if that character set is not ASCII.

It also fails Guido's requirement "no global options", which
is "some other flaw".

Regards,
Martin