Handle CIF fields with a single entry (which are returned as a single…

… item, not alist)
Autodesk · Oct 5, 2017 · fe2720c · fe2720c
1 parent cf86600
commit fe2720c
Showing 1 changed file with 19 additions and 10 deletions.
diff --git a/moldesign/interfaces/parmed_interface.py b/moldesign/interfaces/parmed_interface.py
@@ -261,23 +261,26 @@ def _reassign_chains(f, mol):
     """
     data = mdt.interfaces.biopython_interface.get_mmcif_data(f)
     f.seek(0)
+
     try:
-        newchain_names = set(data['_pdbx_poly_seq_scheme.asym_id']+
-                             data['_pdbx_nonpoly_scheme.asym_id'])
+        poly_seq_ids = _aslist(data['_pdbx_poly_seq_scheme.asym_id'])
+        nonpoly_ids = _aslist(data['_pdbx_nonpoly_scheme.asym_id'])
     except KeyError:
         return mol.copy(name=mol.name)
+
+    newchain_names = set(poly_seq_ids + nonpoly_ids)
     newchains = {name: mdt.Chain(name) for name in newchain_names}
 
     residue_iterator = itertools.chain(
-            zip(data['_pdbx_poly_seq_scheme.mon_id'],
-                data['_pdbx_poly_seq_scheme.pdb_seq_num'],
-                data['_pdbx_poly_seq_scheme.pdb_strand_id'],
-                data['_pdbx_poly_seq_scheme.asym_id']),
+            zip(_aslist(data['_pdbx_poly_seq_scheme.mon_id']),
+                _aslist(data['_pdbx_poly_seq_scheme.pdb_seq_num']),
+                _aslist(data['_pdbx_poly_seq_scheme.pdb_strand_id']),
+                _aslist(data['_pdbx_poly_seq_scheme.asym_id'])),
 
-            zip(data['_pdbx_nonpoly_scheme.mon_id'],
-                data['_pdbx_nonpoly_scheme.pdb_seq_num'],
-                data['_pdbx_nonpoly_scheme.pdb_strand_id'],
-                data['_pdbx_nonpoly_scheme.asym_id']))
+            zip(_aslist(data['_pdbx_nonpoly_scheme.mon_id']),
+                _aslist(data['_pdbx_nonpoly_scheme.pdb_seq_num']),
+                _aslist(data['_pdbx_nonpoly_scheme.pdb_strand_id']),
+                _aslist(data['_pdbx_nonpoly_scheme.asym_id'])))
 
     reschains = {(rname, ridx, rchain): newchains[chainid]
                  for rname, ridx, rchain, chainid in residue_iterator}
@@ -290,3 +293,9 @@ def _reassign_chains(f, mol):
     return mdt.Molecule(mol.atoms,
                         name=mol.name, metadata=mol.metadata)
 
+
+def _aslist(l):
+    if isinstance(l, list):
+        return l
+    else:
+        return [l]