I have used SimpleImputer() to fill the missing values
my_imputer = SimpleImputer()
data_with_imputed_values = my_imputer.fit_transform(train_data)
what I expect is that my dataframe is filled with the mean of that column for the missing cells. yet it only works for one column and doesnt work for the other one.
To explain better the problem, here is the number of missing values before imputation
why does it only work for column-Embarked but not for age?