On 23 July 2016 at 23:01, Eryk Sun <report@bugs.python.org> wrote:
>> I assume you wouldn't expect to support shebang lines
>> like "#!python3.6r"?
>
> That's already supported in py.ini in the [commands] section, per PEP 397.

True, I'd forgotten that. I was meaning for interactive use, which as
you say isn't supported (I asked for it a long time back, but it was
rejected - maybe it's worth revisiting the idea, as I don't recall the
reason for the rejection).

Of course, having two places for launcher configuration, the registry
and the ini file, seems like it would be confusing. So that's an
argument for everything being controlled via the ini file. (BTW, the
documentation in
https://docs.python.org/3/using/windows.html#customization doesn't
give much detail about what can go in the ini file, maybe that needs
improving)