estimator :object type that implements the “fit” and “predict” methods
A object of that type is instantiated for each grid point.
param_grid :dict or list of dictionaries
Dictionary with parameters names (string) as keys and
lists of parameter settings to try as values, or a list of
such dictionaries, in which case the grids spanned by
each dictionary in the list are explored.
This enables searching over any sequence of parameter settings.