yapf format

      valid_frag_inds = [[

          True if np.array(elt).size > 0 else False for elt in f

      ] for f in features]

      features = [[elt for (is_valid, elt) in zip(l, m) if is_valid]

                  for (l, m) in zip(valid_frag_inds, features) if any(l)]

      features = [[elt

                   for (is_valid, elt) in zip(l, m)

                   if is_valid]

                  for (l, m) in zip(valid_frag_inds, features)

                  if any(l)]

    return features

  def _get_atom_properties(self, atom):

      nodes = np.concatenate([nodes, master_atom_features], axis=0)

    # Get bond lists with reverse edges included

    edge_list = [(b.GetBeginAtomIdx(), b.GetEndAtomIdx())

                 for b in mol.GetBonds()]

    edge_list = [

        (b.GetBeginAtomIdx(), b.GetEndAtomIdx()) for b in mol.GetBonds()

    ]

    # Get canonical adjacency list

    canon_adj_list = [[] for mol_id in range(len(nodes))]

    for edge in edge_list: