Formatting floats in Python without superfluous zeros

Question

How to format a float so it does not containt the remaing zeros? In other words, I want the resulting string to be as short as possible..?

Like:

3 -> "3"
3. -> "3"
3.1 -> "3.1"
3.14 -> "3.14"
3.140 -> "3.14"

Answer 1

You could use %g to achieve this:

'%g'%(3.140)

or, for Python 2.6 or better:

'{0:g}'.format(3.140)

From the docs for format: g causes (among other things)

insignificant trailing zeros [to be] removed from the significand, and the decimal point is also removed if there are no remaining digits following it.

Answer 2

Me, I'd do ('%f' % x).rstrip('0').rstrip('.') -- guarantees fixed-point formatting rather than scientific notation, etc etc. Yeah, not as slick and elegant as %g, but, it works (and I don't know how to force %g to never use scientific notation;-).