Return bool from SymOp.is_identity.

Author: pavoljuhas

src/diffpy/Structure/spacegroupmod.py

@@ -137,9 +137,11 @@ def is_identity(self):
         """Returns True if this SymOp is an identity symmetry operation
         (no rotation, no translation), otherwise returns False.
         """
-        if numpy.allclose(self.R, numpy.identity(3, float)) and \
-           numpy.allclose(self.t, numpy.zeros(3, float)):
-            return True
+        rv = (numpy.allclose(self.R, numpy.identity(3, float)) and
+              numpy.allclose(self.t, numpy.zeros(3, float)))
+        return rv
+
+# End of class SymOp
 
 
 class SpaceGroup(object):
@@ -191,6 +193,8 @@ def iter_equivalent_positions(self, vec):
         """
         for symop in self.symop_list:
             yield symop(vec)
+        pass
 
+# End of class SpaceGroup
 
 # End of file