variable number of digit in format string

Question

Which is a clean way to write this formatting function:

def percent(value,digits=0):
    return (\'{0:.%d%%}\' % digits).format(value)

>>> percent(         


        

Answer 1

From the docs:

Minimum field width (optional). If specified as an '*' (asterisk), the actual width is read from the next element of the tuple in values, and the object to convert comes after the minimum field width and optional precision.

Example:

def percent(value, digits=0):
    print '%.*f%%' % (digits, value*100)
>>> percent(0.1565, 2)
15.65%