or (n_samples,), default=None Target relative to X for classification or regression; None for unsupervised learning. **params : dict Parameters to be passed to the underlying scorer(s). .. versionadded:: 1.4 Only available if `enable_metadata_routing=True`. See :ref:`Metadata Routing User Guide ` for more details. Returns ------- score : float The score defined by ``scoring`` if provided, and the ``best_estimator_.score`` method otherwise. Ú