Add padding to a number in Python

This post will discuss how to add padding to a number in Python.

1. Using `str.rjust()` function

A simple approach to add padding to a number is using the str.rjust() function, which takes the length and the fill character.

if __name__ == '__main__':

i = 1111

pad = '0'

n = 8

x = str(i).rjust(n, pad)

print(x) # 00001111

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2. Using `str.zfill()` function

Another alternative to convert a number to a specified length left-padded with 0’s is using the str.zfill() function.

if __name__ == '__main__':

i = 1111

n = 8

x = str(i).zfill(n)

print(x) # 00001111

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3. Using f-strings

Starting with Python 3.6, you can use f-strings.

if __name__ == '__main__':

i = 1111

pad = '0'

n = 8

x = f'{i:{pad}{n}}' # x = f'{i:08}'

print(x) # 00001111

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4. Using `str.format()` function

Before Python 3.6, you can use general string formatting with the str.format() function.

if __name__ == '__main__':

i = 1111

pad = '0'

n = 8

x = ('{:' + pad + str(n) + '}').format(i) # x = '{:08}'.format(i)

print(x) # 00001111

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5. Using built-in `format()` function

Finally, you can use the built-in function format() to add padding to a number.

if __name__ == '__main__':

i = 1111

pad = '0'

n = 8

x = format(i, pad + str(n)) # x = format(i, '08')

print(x) # 00001111

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That’s all about adding padding to a number in Python.

Add padding to a number in Python

1. Using str.rjust() function

2. Using str.zfill() function

3. Using f-strings

4. Using str.format() function

5. Using built-in format() function

Share this:

1. Using `str.rjust()` function

2. Using `str.zfill()` function

4. Using `str.format()` function

5. Using built-in `format()` function