Home » How to Select Rows with NaN Values in Pandas (With Examples)

How to Select Rows with NaN Values in Pandas (With Examples)

by Erma Khan

You can use the following methods to select rows with NaN values in pandas:

Method 1: Select Rows with NaN Values in Any Column

df.loc[df.isnull().any(axis=1)]

Method 2: Select Rows with NaN Values in Specific Column

df.loc[df['this_column'].isnull()]

The following examples show how to use each method in practice with the following pandas DataFrame:

import pandas as pd
import numpy as np

#create DataFrame
df = pd.DataFrame({'team': ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H'],
                   'points': [18, np.NaN, 19, 14, 14, 11, 20, 28],
                   'assists': [5, 7, 7, 9, np.NaN, 9, 9, np.NaN],
                   'rebounds': [11, 8, 10, 6, 6, 5, 9, np.NaN]})

#view DataFrame
print(df)

Example 1: Select Rows with NaN Values in Any Column

We can use the following syntax to select rows with NaN values in any column of the DataFrame:

#create new DataFrame that only contains rows with NaNs in any column
df_nan_rows = df.loc[df.isnull().any(axis=1)]

#view results
print(df_nan_rows)

  team  points  assists  rebounds
1    B     NaN      7.0       8.0
4    E    14.0      NaN       6.0
7    H    28.0      NaN       NaN   

Notice that each row in the resulting DataFrame contains a NaN value in at least one column.

Example 2: Select Rows with NaN Values in Specific Column

We can use the following syntax to select rows with NaN values in the assists column of the DataFrame:

#create new DataFrame that only contains rows with NaNs in assists column
df_assists_nans = df.loc[df['assists'].isnull()]
#view results
print(df_assists_nans)

  team  points  assists  rebounds
4    E    14.0      NaN       6.0
7    H    28.0      NaN       NaN   

Notice that each row in the resulting DataFrame contains a NaN value in the assists column.

There is one row with a NaN value in the points column, but this row is not selected since it doesn’t have a NaN value in the assists column as well.

Additional Resources

The following tutorials explain how to perform other common tasks in pandas:

Pandas: How to Drop Rows with NaN Values
Pandas: How to Replace NaN Values with String
Pandas: How to Fill NaN Values with Mean

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