Python string format width

Question

I am having problems replicating the format as shown in:

what my results are:

I'm currently using:

print '{}.{:<20} {}.'.format(i,'sum so far:',sum)

I have tried left, right, and center alignment, but I just can't get the format that I want.

Answer 1

Convert the entire header portion, including the '.', to a string first, so you can calculate the width including it.

>>> '{:<20} sum so far: {}.'.format('{}.'.format(9), 123)
'9.                   sum so far: 123.'
>>> '{:<20} sum so far: {}.'.format('{}.'.format(10), 123)
'10.                  sum so far: 123.'