fixup! xml_marshaller: add support for Python 3

src/xml_marshaller/xml_marshaller.py

@@ -596,11 +596,13 @@ class Unmarshaller(ElementTreeContentHandler):
       try:
         value = klass(*initargs)
       except TypeError as err:
-        reraise(TypeError, 'in constructor for %s: %s' % (
-            klass.__name__, err), sys.exc_info()[2])
+        reraise(TypeError, TypeError('in constructor for %s: %s' % (
+            klass.__name__, err)), sys.exc_info()[2])
 
     # Now set the object's attributes from the marshalled dictionary
     for k, v in kw.items():
+      if not isinstance(k, str):
+        k = k.decode()
       setattr(value, k, v)
     self.data_stack[-5:] = [value]