change attr setting

Author: JacksonBurns

rmgpy/molecule/molecule.py

@@ -1034,8 +1034,6 @@ def __init__(self, atoms=None, symmetry=-1, multiplicity=-187, reactive=True, pr
         self.props = props or {}
         self.metal = metal
         self.facet = facet
-        self._sssr = None
-        self._symm_sssr = None
 
         if inchi and smiles:
             logging.warning('Both InChI and SMILES provided for Molecule instantiation, '
@@ -2663,10 +2661,10 @@ def get_smallest_set_of_smallest_rings(self, symmetrized=False):
         though RMG uses SSSR for historical reasons.
         """
         if symmetrized:
-            if self._symm_sssr is not None:
+            if hasattr(self, "_symm_sssr"):
                 return self._symm_sssr
         else:
-            if self._sssr is not None:
+            if hasattr(self, "_sssr"):
                 return self._sssr
 
         # RDKit does not support electron
@@ -2691,6 +2689,10 @@ def get_smallest_set_of_smallest_rings(self, symmetrized=False):
             atom_ring = [self.atoms[idx] for idx in ring]
             sorted_ring = self.sort_cyclic_vertices(atom_ring)
             sssr.append(sorted_ring)
+        if symmetrized:
+            setattr(self, "_symm_sssr", sssr)
+        else:
+            setattr(self, "_sssr", sssr)
         return sssr
 
     def get_relevant_cycles(self):