code: def _move_centroids(self):
          
          for k in range(self.n_clusters):
              if k in self.clusters:
                  centroid = np.mean(self._X[self.clusters == k, :], axis=0)
                  self.centroids[k] = centroid
  
              else:
                  self.n_clusters-=1
                  self.centroids = self.centroids[:self.n_clusters]
                  self.clusters-=1
                  k-=1
docs: Calculate new centroids as the means of the samples in each cluster