ImportError: cannot import name 'Categorical Imputer' from 'sklearn pandas' (C:\Users\k-alw\anaconda3\lib\site-packages\sklearn_pandas\__init__.py) code example

Example 1: cannot import name 'imputer'

from sklearn.impute import SimpleImputer 
imputer = SimpleImputer(missing_values=np.nan, strategy='mean')

Example 2: cannot import name 'imputer' from 'sklearn.preprocessing'

from sklearn.impute import SimpleImputer
imputer = SimpleImputer(missing_values=np.nan, strategy='mean')