Update test_compmixin.py

for Python 3.13, maybe

Origin: spacetelescope/stsci.tools#164

Author: pllim

pyraf/tools/tests/test_compmixin.py

@@ -35,6 +35,9 @@ def _compare(self, other, method):
         elif other is None:
             # coerce to str compare
             return method(str(self.val), '')
+        elif self.val is None:
+            # coerce to str compare
+            return method('', str(other))
         elif isinstance(other, int):
             # handle ONLY case where self.val is a single char or an int
             if isinstance(self.val, str) and len(self.val) == 1: