Python Modulo | % Operator, math.fmod() Examples

There are several uses for a Python modulo operation, including finding the remainder of a division and creating ciphers. The modulo operator (%) belongs to the arithmetic operations along with +, -, /, *, **, //. The remainder is returned after dividing the left operand/number by the right operand/number.

This post provides an in-depth guide on the Python modulo operator and “math.fmod()” function using various examples:

  • Using Python Modulo – % Operator
    • Performing Basic Calculation Using Modulo Operator 
    • Exception Handling Using % Operator
  • Using math.fmod() Function
    • Using math.fmod() to Get Modulo of Numbers
    • Using math.fmod() on List Values

Using Python Modulo – % Operator

In Python, the modulo operator “%” is utilized to retrieve the remainder of the two divisible numbers. For instance, the number “10” divided by the number “3” will return the “1” as a remainder output. This remainder output will be found using the modulo operator “%.” 

Let’s understand it by the following examples:

Note: You can also check this specific guide for an in-depth understanding of the Python modulo % operator.

Example 1: Basic Calculation Using Modulo Operator 

The below code is used to perform a basic calculation using the modulo operator:

Code: 

print(10%3)
print(9%3.0)
print(-5%3)
print(-10%3)

The “%” operator is used to find the remainder value of the positive and negative numbers.

Output: 

Example 2: Exception Handling Using % Operator

The below code will throw a zero division error when the positive or negative number is divided by zero:

Code:

try:
    print(15 % 0)
except ZeroDivisionError:
    print("We cannot divide by 0")

The “try” block will execute the code and find the remainder of the number. If the “ZeroDivisionError” occurs, the “except” block handles the error.

Output:

The exception has been printed.

Using math.fmod() Function

The built-in function “math.fmod()” is used to find the remainder (modulo) of two given numbers as a float similar to the Python “%” operator. For example, math.fmod(5.5, 2) returns 1.5.  However, it behaves differently from the modulo operator when dealing with negative or floating point numbers. 

Let’s see different examples of the “math.fmod()” function:

Example 1:Using math.fmod() to Get Modulo of Numbers

The below code is used to find the remainder of a number using the “fmod()” function:

Code: 

import math
print(math.fmod(15, 4))
print(math.fmod(-24, 7))
print(math.fmod(222, -7))
print(math.fmod(15, 6))

The “math.fmod()” function is used to return the remainder of the number by accepting the numerator and denominator as an argument.

Output:

The remainder has been returned successfully.

Example 2: Using math.fmod() on List Values

The below code is used to perform a modulo operation on elements of a list using the “math.fmod()” function:

Code: 

import math
List = [-6, 8, -9, 3]
print(math.fmod(List[3], 2))
print(math.fmod(List[0], -4))

The “math.fmod()” takes the index value of the list as a first argument and divides it to the value of the second argument. This function returns the remainder value.

Output: 

The remainder of the specific divisible number has been returned.

Conclusion

The Python modulo operator “%” and “math.fmod()” function of the math module is utilized to return the remainder of the two divisible numbers.  The “math.fmod()” function is similar to the simple Python modulo operator “%” for positive numbers. But it behaves differently than the modulo operator when it comes to negative numbers or floating point numbers. This guide has presented an in-depth overview of the Python modulo operator and math.fmod() function using numerous examples.