# Python Modulo

Summary: in this tutorial, you’ll learn about the Python modulo operator (`%`) and how to use it effectively.

## Introduction to the Python modulo operator

Python uses the percent sign (%) as the modulo operator. The modulo operator always satisfies the following equation:

`N = D * ( N // D) + (N % D)`

Code language: JavaScript (javascript)

In this equation:

• N is the numerator.
• D is the denominator.
• // is the floor division operator
• And % is the modulo operator

If both N and D are positive integers, the modulo operator returns the remainder of N / D. However, it is not the case for the negative numbers. Therefore, you should always stick with the above equation.

## Simple Python modulo operator examples

The following example illustrates how to use the modulo operator (%) with positive integers:

`a = 16 b = 5m = a % b f = a // b# show the result`

`print(f'{a} % {b} = {m}') # 1 print(f'{a} // {b} = {f}') # 3`

Code language: Python (python)

Output:

`1 3`

For positive numbers, the result is quite apparent. And you can check the equation quickly:

`16 = 5 * (16 // 5) + 16 % 5 16 = 5 * 3 + 1`

Code language: JavaScript (javascript)

The following shows how to use the modulo operator (`%`) with negative integers:

`a = -16 b = 5m = a % b f = a // b# show the result`

`print(f'{a} % {b} = {m}') # 4 print(f'{a} // {b} = {f}') # -4`

Code language: Python (python)

And the equation is satisfied:

`-16 = 5 * (-16 % 5) + (-16) % 5 -16 = 5 * -4 - 4`

## Practical Python modulo operator examples

Let’s take some practical examples of using the modulo operator (%)

### 1) Using the modulo operator to check if a number is even or odd

The following defines a function that uses the modulo operator (%) to check if a number is even:

`def is_even(num): return num % 2 == 0 `

Code language: Python (python)

And the following defines a function that uses the modulo operator to check if a number is odd:

`def is_odd(num): return num % 2 != 0 `

Code language: JavaScript (javascript)

### 2) Using the modulo operator to convert units

The following example uses the modulo operator (`%`) to convert seconds to days, hours, minutes, and seconds. It can be handy if you want to develop a countdown program:

`from math import floordef get_time(total_seconds): return { 'days': floor(total_seconds / 60 / 60 / 24), 'hours': floor(total_seconds / 60 / 60) % 24, 'minutes': floor(total_seconds / 60) % 60, 'seconds': total_seconds % 60, }`

`print(get_time(93750))`

Code language: Python (python)

Output:

`{'days': 1, 'hours': 2, 'minutes': 2, 'seconds': 30}`

Code language: JavaScript (javascript)

## Summary

• Python uses the percent sign (`%`) as the modulo operator.
• The modulo operator (%) always satisfies the equation `N = D * ( N // D) + (N % D)`.