# Python: Integers formatting

Hi,

I am having trouble trying to format a simple list of integers: The aim is to format integers so when I print them I get double digits. So basically -1 shoud become -01, 0 becomes 00, 1 becomes 01 etc. I have manage to make it work for positive numbers but all the negative values don’t seem to change. I’m not looking for a work around, I would like to know the correct python expression if there is any.

Any ideas?
@Helvetosaur, @djordje, @AndersDeleuran

``````levels = range(-3,21)

for level in levels:
print(level,'LVL {:02d}'.format(level))

"""
Output:
(-3, 'LVL -3') --> needs to be + (-3, 'LVL -03')
(-2, 'LVL -2') --> needs to be + (-3, 'LVL -02')
(-1, 'LVL -1')  --> needs to be + (-3, 'LVL -01')
(0, 'LVL 00')
(1, 'LVL 01')
(2, 'LVL 02')
(3, 'LVL 03')
"""
``````

-Miguel

Hi Miguel,

This seems to work:

``````

levels = range(-3,21)

for level in levels:

if integer < 0:
# expect an extra character
return '{:03d}'.format(integer)

else:
return '{:02d}'.format(integer)

``````

result:

``````(-3, 'LVL -03')
(-2, 'LVL -02')
(-1, 'LVL -01')
(0, 'LVL 00')
(1, 'LVL 01')
(2, 'LVL 02')
(3, 'LVL 03')
...
``````

Hi Willem,

I’m guessing python is counting the “-” minus sign.

Thanks again,

-Miguel

Actually this was just a trial and error for me…no clue if it is pythonesque.

I’m guessing python is measuring the len() of the string created, hence the extra character needed.

This gives what you’re looking for. The space in the format string (’% 03d’) will print a space for positive values and a ‘-’ for negative ones.

``````levels = range(-3,21)
for level in levels:
print( level, 'LVL % 03d'%level)
``````