diff --git a/pyscf/pbc/symm/pyscf_spglib.py b/pyscf/pbc/symm/pyscf_spglib.py
index 2bdeff2b64..3a0d1442cb 100644
--- a/pyscf/pbc/symm/pyscf_spglib.py
+++ b/pyscf/pbc/symm/pyscf_spglib.py
@@ -38,8 +38,7 @@ def cell_to_spgcell(cell):
         atm_num.append(elements.NUC[symbol])
     for iatm in range(cell.natm):
         symb = cell.atom_symbol(iatm)
-        idx = ''.join([i for i in symb if unicode(i).isnumeric()])
-        idx = unicode(idx)
+        idx = ''.join([i for i in symb if i.isnumeric()])
         if idx.isnumeric():
             atm_num[iatm] += int(idx) * 1000
     spg_cell = (a, atm_pos, atm_num, cell.magmom)
diff --git a/pyscf/solvent/pol_embed.py b/pyscf/solvent/pol_embed.py
index 6a8b66c9d1..5778b33dec 100644
--- a/pyscf/solvent/pol_embed.py
+++ b/pyscf/solvent/pol_embed.py
@@ -47,7 +47,8 @@
 
 import cppe
 from packaging.version import parse as _parse_version
-if _parse_version(cppe.__version__) < _parse_version('0.3.1'):
+min_version = '0.3.1'
+if _parse_version(cppe.__version__) < _parse_version(min_version):
     raise ModuleNotFoundError("cppe version {} is required at least. "
                               "Version {} was found.".format(min_version, cppe.__version__))