How can I check for NaN values?

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Chapters
00:00 How Can I Check For Nan Values?
00:13 Accepted Answer Score 2215
00:23 Answer 2 Score 626
00:36 Answer 3 Score 305
00:45 Answer 4 Score 266
01:02 Thank you

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Full question
https://stackoverflow.com/questions/9447...

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Content licensed under CC BY-SA
https://meta.stackexchange.com/help/lice...

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Tags
#python #math

#avk47

ACCEPTED ANSWER

Score 2215

Use math.isnan:

>>> import math
>>> x = float('nan')
>>> math.isnan(x)
True

ANSWER 2

Score 626

The usual way to test for a NaN is to see if it's equal to itself:

def isNaN(num):
    return num != num

ANSWER 3

Score 305

numpy.isnan(number) tells you if it's NaN or not.

ANSWER 4

Score 266

Here are three ways where you can test a variable is "NaN" or not.

import pandas as pd
import numpy as np
import math

# For single variable all three libraries return single boolean
x1 = float("nan")

print(f"It's pd.isna: {pd.isna(x1)}")
print(f"It's np.isnan: {np.isnan(x1)}}")
print(f"It's math.isnan: {math.isnan(x1)}}")

Output:

It's pd.isna: True
It's np.isnan: True
It's math.isnan: True