Docstring is inherited from the LGBMModel.

def fit(self, X, y,
            sample_weight=None, init_score=None,
            eval_set=None, eval_names=None, eval_sample_weight=None,
            eval_class_weight=None, eval_init_score=None, eval_metric=None,
            early_stopping_rounds=None, verbose=True,
            feature_name='auto', categorical_feature='auto', callbacks=None):
        """Docstring is inherited from the LGBMModel."""
        _LGBMAssertAllFinite(y)
        _LGBMCheckClassificationTargets(y)
        self._le = _LGBMLabelEncoder().fit(y)
        _y = self._le.transform(y)

        self._classes = self._le.classes_
        self._n_classes = len(self._classes)
        if self._n_classes > 2:
            # Switch to using a multiclass objective in the underlying LGBM instance
            ova_aliases = ("multiclassova", "multiclass_ova", "ova", "ovr")
            if self._objective not in ova_aliases and not callable(self._objective):
                self._objective = "multiclass"
            if eval_metric in ('logloss', 'binary_logloss'):
                eval_metric = "multi_logloss"
            elif eval_metric in ('error', 'binary_error'):
                eval_metric = "multi_error"
        else:
            if eval_metric in ('logloss', 'multi_logloss'):
                eval_metric = 'binary_logloss'
            elif eval_metric in ('error', 'multi_error'):
                eval_metric = 'binary_error'

        if eval_set is not None:
            if isinstance(eval_set, tuple):
                eval_set = [eval_set]
            for i, (valid_x, valid_y) in enumerate(eval_set):
                if valid_x is X and valid_y is y:
                    eval_set[i] = (valid_x, _y)
                else:
                    eval_set[i] = (valid_x, self._le.transform(valid_y))

        super(LGBMClassifier, self).fit(X, _y, sample_weight=sample_weight,
                                        init_score=init_score, eval_set=eval_set,
                                        eval_names=eval_names,
                                        eval_sample_weight=eval_sample_weight,
                                        eval_class_weight=eval_class_weight,
                                        eval_init_score=eval_init_score,
                                        eval_metric=eval_metric,
                                        early_stopping_rounds=early_stopping_rounds,
                                        verbose=verbose, feature_name=feature_name,
                                        categorical_feature=categorical_feature,
                                        callbacks=callbacks)
        return self