If you're using round(str(some_float), digits) and the result is a float, then that's a problem, since you're going to round it again for display at some point.

If you want a string result, you're better off using format(float, format_spec), or f-strings, or str.format() (all of which have the same underlying implementation) to do your float-to-string-for-display-purposes work.

I just don't see how getting a binary float via decimal rounding would be useful.