The **modulo operator** is used in Python programming when you need to find the remainder of integer division. It comes up in many important algorithms, and is represented by the symbol `%`

. The `%`

operator gives the result of dividing the number on the left of the symbol by the number on the right and keeping the remainder.

For example:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 |
for i in range(1, 11): print("10 % {} = {}".format(i, 10 % i)) Output: 10 % 1 = 0 10 % 2 = 0 10 % 3 = 1 10 % 4 = 2 10 % 5 = 0 10 % 6 = 4 10 % 7 = 3 10 % 8 = 2 10 % 9 = 1 10 % 10 = 0 |

Check these divisions for yourself and make sure you understand why the results are what they are.

## Even and Odd in Python

One very common use of the **modulo** operator is to determine whether an integer is even or odd. Have a think about how you might do this yourself before revealing the code below. *Hint: One way to think of oddness and evenness of integers is to consider what happens when you divide them by two.*

There are many other applications for the **modulo** operator in Python programming. Particularly in Cryptography. One very common use is in the classic software developer interview question **Fizz Buzz**:

Fizz Buzz is a game for two or more players. Take it in turns to count aloud from 1 to 50, but each time you are going to say a multiple of 3, replace it with the word “Fizz”. For multiples of 5, say “Buzz” and for numbers which are multiples of both 3 and 5, say “Fizz Buzz”.

Have a go at coding this for yourself before looking a the solution below. You don’t need to worry about there being two players. Just loop through the numbers from 1-50 and output **“Fizz”**, **“Buzz”** or **“Fizz Buzz”** as required.

## Python Solution for the Classic Fizz Buzz Interview Problem

So there you have it. The modulo operator in Python. Definitely one to add to your Python programming toolkit!

Happy Computing!