Almost. If you use that regular expression, then a user who
> planned on writing '.5' wouldn't be able to type the leading
> '.'. One could use r'^(\d*\.\d*)$' with some post-processing
> afterwards to make it so that an empty entry or just a plain
> '.' turns into a zero.
Or r'^(\.\d+\|\d+\.\d*\)' -- that way dot alone is disallowed
directly.
paul