Introduction Python isnan() Method with Examples

Python isnan() method is a library method of math module, it is used to check whether a given number is “NaN” (Not a Number) or not, it accepts a number and returns True if given number is “NaN”, else it returns False.

Python isnan()

Syntax

math.isnan(x)

Parameter(s):

• x – a number that has to be checked whether it is “NaN” or not.

Return value:

The isnan() function returns two types of value:

• True: If the given parameter is not a number

• False: If the given parameter is a number

Examples of Python isnan() method

Example 1

# python code to demonstrate example of 
# math.isnan() method

# importing math module
import math

# math.isnan() method test on finite value
print(math.isnan(10))
print(math.isnan(0))
print(math.isnan(10.23))
print(math.isnan(0.0))


# math.isnan() method test on infinite and NaN value
print(math.isnan(float('inf')))
print(math.isnan(float('-inf')))
print(math.isnan(float('nan')))

Output

False
False
False
False
False
True

In the example above , we have imported the math library, and then we have checked the output of the isnan() function using various input.
We have checked output for integer, float, and negative numbers, respectively; for all these cases, the output is False. Then we have checked output for nan, here the output is True because nan is not a number.

Example 2

import math

# checking isnan() values
print(math.isnan(math.pi))
print(math.isnan(math.e))

Output

False
False

If you want to check for NaN values in Python, then use the Python isnan() function provided by the math library.

Thanks for reading !

#python #programming