Multiple types of processing: FunctionTransformer

The next two exercises will introduce new topics you'll need to make your pipeline truly excel.

Any step in the pipeline must be an object that implements the fit and transform methods. The FunctionTransformer creates an object with these methods out of any Python function that you pass to it. We'll use it to help select subsets of data in a way that plays nicely with pipelines.

You are working with numeric data that needs imputation, and text data that needs to be converted into a bag-of-words. You'll create functions that separate the text from the numeric variables and see how the .fit() and .transform() methods work.

Compute the selector get_text_data by using a lambda function and FunctionTransformer() to obtain all 'text' columns.
Compute the selector get_numeric_data by using a lambda function and FunctionTransformer() to obtain all the numeric columns (including missing data). These are 'numeric' and 'with_missing'.
Fit and transform get_text_data using the .fit_transform() method with sample_df as the argument.
Fit and transform get_numeric_data using the same approach as above.

Exercise

Multiple types of processing: FunctionTransformer

Instructions