How to use Python Modulo – with example

What is Python modulo used for?
Examples for Python modulo
Summary
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What is Python modulo used for?

The modulo operator in Python is used to return the remainder when performing division between two numbers. The modulo operator is simple and yet it is widely used in Python and programming in general.

Examples for Python modulo

To explore the functionality of the Python modulo operator we are going to create two integer variables. Besides the modulo operator, there are a number of other useful operators that perform different operations in Python.

For instance, the star sign is used to denote multiplication between two numbers.

We can also perform the division operation between two numbers using the forward slash. As shown below.

The Python modulo operator is considered an arithmetic operation and is denoted by the per cent sign. The modulo operator returns the remainder when one number is divided by another.

In the case above since the numbers are divisible, the remainder is zero. Because when we divide 10 by 2 the result is 5 and there is no remainder in this case.

However, If we change the divisor to three, we are going to get a remainder, since ten divided by three is not a whole number. So we actually have one leftover because three goes into 10 three times with one as the remainder.

Now the Python modulo operator is particularly useful in cases where we might want to work out whether a number is odd or even.

We can actually write a short if statement, that will compare two numbers and tell us whether a number is odd or even, based on the remainder given.

So normally we know that all even numbers are divisible by two and therefore the remainder is always zero, for example since 10 is an even number if we try to divide it by two the remainder is always zero.

However, if we try 11 which is an odd number we will definitely get a remainder. This is because all odd numbers are not divisible by two.

On the other hand, if we try 12 we definitely get a zero as the remainder, since 12 is an even number.

Using an if statement we can write a conditional statement, such that if the actual outcome a%b is zero then we’re going to print out an even number.

On the other hand, if the outcome of the Python modulo operation is not zero, we should print out odd.

So we know that in the case above we should get even since 12 is an even number. In this case, Python is letting us know that a dividend is an even number.

A better way of writing the above code would be using the divisor which is two in this case directly in the code since we do not intend to change it as shown below.

We can also try out a different number which in this case is going to return that the dividend, in this case, is an odd number.

This method is quite useful when testing out large numbers to ascertain whether they are even or odd.

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