Fixed width number formatting python 3

Question

How do I get an integer to fill 0's to a fixed width in python 3.2 using the format attribute? Example:

a = 1
print('{0:3}'.format(a))

gives ' 1' instead of '001' I want. In python 2.x, I know that this can be done using

print "%03d" % number.

I checked the python 3 string documentation but wasn't able to get this.

Thanks.

user_2840531 · Answer

Better:

number=12
print(f'number is equal to {number:03d}')

user_8663760 · Answer

There is built-in string method .zfill for filling 0-s:

>>> str(42).zfill(5)
'00042'
>>> str(42).zfill(2)
'42'