# math.isnan() method with example in Python

Python math.isnan() method: Here, we are going to learn about the math.isnan() method with example in Python.
Submitted by IncludeHelp, on April 18, 2019

## Python math.isnan() method

math.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.

Syntax of math.isnan() method:

```    math.isnan(n)
```

Parameter(s): n – a number that has to be checked whether it is "NaN" or not.

Return value: bool – it returns a Boolean ("True" or "False") value.

Example:

```    Input:
a = 10
b = float('inf')
c = float('nan')

# function call
print(math.isnan(a))
print(math.isnan(b))
print(math.isnan(c))

Output:
False
False
True
```

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

```# 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
```