code: def is_connected(C, directed=True):
      r
      nc = csgraph.connected_components(C, directed=directed, connection='strong', \
                                        return_labels=False)
      return nc == 1
docs: r"""Return true, if the input count matrix is completely connected.
      Effectively checking if the number of connected components equals one.
  
      Parameters
      ----------
      C : scipy.sparse matrix or numpy ndarray
          Count matrix specifying edge weights.
      directed : bool, optional
         Whether to compute connected components for a directed  or
         undirected graph. Default is True.
  
      Returns
      -------
      connected : boolean, returning true only if C is connected.