Couple of potential "improvements" #3
Description
Not really necessary but just for posterity.
round_() could be written more concisely:
http://stackoverflow.com/a/3411435/2921610
general form could be emulated more closely with an optional range modifier (e.g. 'e' format for e < -2 rather than -4).
Comma separated values should be available in string() really if large numbers are to be employed.
All this is is probably niche use though so maybe.