特征处理流程

简单示例

def get_feature_conf():
    feature_confs = []
    feature_confs.append(
        Feature("item_id").add_op(SelectField("item_id")).add_op(Hash("farm"))
    )
    feature_confs.append(
        Feature("user_id").add_op(SelectField("user_id")).add_op(Hash("farm"))
    )
    feature_confs.append(
        Feature("rate").add_op(SelectField("rate")).add_op(Bucketize([0, 0.1, 0.2]))
    )
    return feature_confs