code: def find_connecting_throat(self, P1, P2):
          r
          am = self.create_adjacency_matrix(weights=self.Ts, fmt='coo')
          sites = sp.vstack((P1, P2)).T
          Ts = topotools.find_connecting_bonds(sites=sites, am=am)
          return Ts
docs: r"""
          Return the throat index connecting pairs of pores
  
          Parameters
          ----------
          P1 , P2 : array_like
              The indices of the pores whose throats are sought.  These can be
              vectors of indices, but must be the same length
  
          Returns
          -------
          Returns a list the same length as P1 (and P2) with the each element
          containing the throat index that connects the corresponding pores,
          or `None`` if pores are not connected.
  
          Notes
          -----
          The returned list can be converted to an ND-array, which will convert
          the ``None`` values to ``nan``.  These can then be found using
          ``scipy.isnan``.
  
          Examples
          --------
          >>> import openpnm as op
          >>> pn = op.network.Cubic(shape=[5, 5, 5])
          >>> Ts = pn.find_connecting_throat([0, 1, 2], [2, 2, 2])
          >>> print(Ts)
          [None, 1, None]