Check if single cell value is NaN in Pandas

Question

I just want to check if a single cell in Pandas series is null or not i.e. to check if a value is NaN.

All other answers are for series and arrays, but

Answer 1

You can use "isnull" with "at" to check a specific value in a dataframe.

For example:

import pandas as pd
import numpy as np

df = pd.DataFrame([[np.nan, 2], [1, 3], [4, 6]], columns=['A', 'B'])

Yeilds:

    A   B
0   NaN 2
1   1.0 3
2   4.0 6

To check the values:

pd.isnull(df.at[0,'A'])

-> True

pd.isnull(df.at[0,'B'])

-> False