def _reset(self):
        """
        Reset internal data-dependent state of the scaler, if necessary.
        __init__ parameters are not touched.

        """

        # Checking one attribute is enough, because they are all set together
        # in partial_fit
        if hasattr(self, 'scale_'):
            del self.scale_
            del self.n_samples_seen_
            del self.mean_
            del self.var_
Reset internal data-dependent state of the scaler, if necessary.
        __init__ parameters are not touched.