PYTHON

fill missing values in column pandas with mean

df.fillna(df.mean(), inplace=True)

pandas fill missing values with average

# Fill colB na's with avg of colA Groupings 
df.groupby('colA')['colB'].transform(lambda value: value.fillna(value.mean()))
# Fill missing Lot Frontage with avg for Neighborhood 
df.groupby('Neighborhood')['Lot Frontage'].transform(lambda value: value.fillna(value.mean()))

how to fill missing values dataframe with mean

sub2['income'].fillna((sub2['income'].mean()), inplace=True)