Hydra-Sklearn Blog - Code example 3

hydra_config_file.yaml

# Hydra config file for the decision_tree preprocessing steps
_target_: hydra_sklearn_pipeline.make_pipeline

#StepName:
#    _target_: <class to instantiate the step>
#    param1: <step's first parameter>
#    param2: <step's second parameter, etc.>

steps_config: # use yaml list syntax to preserve to order
    - StandardScaler:
        _target_: sklearn.preprocessing.StandardScaler

    - VarianceThreshold:
        _target_: sklearn.feature_selection.VarianceThreshold
        threshold: 0.1

    - SimpleImputer:
        _target_: sklearn.impute.SimpleImputer
        strategy: 'constant'
        fill_value: '-1'