Fill in missing data by group with pandas

fill_missing_data_bygroup.py

#EXAMPLE USING TITANIC DATASET

# Create a groupby object: by_sex_class
by_sex_class = titanic.groupby(['sex', 'pclass'])

# Write a function that imputes median
def impute_median(series):
    return series.fillna(series.median())

# Impute age and assign to titanic['age']
titanic.age = by_sex_class.age.transform(impute_median)

# Print the output of titanic.tail(10)
print(titanic.tail(10))