import numpy as np # linear algebra
import pandas as pd # data processing, CSV file I/O (e.g. pd.read_csv)

# dataset: https://www.kaggle.com/camnugent/california-housing-prices
df = pd.read_csv('/kaggle/input/california-housing-prices/housing.csv');

print('\nisnull before:\n', df['total_bedrooms'].isnull().any())
# isnull before:
#  True

df['total_bedrooms'].fillna(df['total_bedrooms'].median(), inplace=True)

print('\nisnull after:\n', df['total_bedrooms'].isnull().any())
# isnull after:
#  False