Don't use .values when passing a pandas object to scikit-learn

[@dataschool]

Want more scikit-learn tips? Check out this playlist: ruclips.net/p/PL5-da3qGB5ID7YYAqireYEew2mWVvgmj6

[@rachitban]

We add .values just to make it more speedy so that it doesn't have to convert to numpy array by itself.

[@dataschool]

That's fine, though that means you won't be able to access columns by name with ColumnTransformer, and starting in scikit-learn 1.0 (coming soon) you will miss out on some additional functionality with respect to feature names.