From D

[Ryan Ginstrom]

> On Behalf Of Leo Petr
> Digits are grouped in 2s in India and in 4s in China and Japan.

This is not entirely true in Japan's case. When written without Japanese
characters, Japan employs the same format as the US, for example:

1,000,000
(However, they would read this as 百万 (hyaku man), literally 100 ten
thousands.)

Raymond is correct in that Japan traditionally groups in fours (and stills
reads it that way regardless, as shown above), but in an ordinary
programming context, this almost never comes into play.

On the original topic of the thread, I personally like the underscore idea
from D, and I like it better than the "concatenation" idea, even though I
agree that it is more consistent with Python's string-format rules.

Regards,
Ryan Ginstrom