python – Display number with leading zeros

In Python 2 (and Python 3) you can do:

number = 1
print(%02d % (number,))

Basically % is like printf or sprintf (see docs).

For Python 3.+, the same behavior can also be achieved with format:

number = 1
print({:02d}.format(number))

For Python 3.6+ the same behavior can be achieved with f-strings:

number = 1
print(f{number:02d})

You can use str.zfill:

print(str(1).zfill(2))
print(str(10).zfill(2))
print(str(100).zfill(2))

prints:

01
10
100

In Python 2.6+ and 3.0+, you would use the format() string method:

for i in (1, 10, 100):
    print({num:02d}.format(num=i))

or using the built-in (for a single number):

print(format(i, 02d))

See the PEP-3101 documentation for the new formatting functions.