[xmlparser.py] Catch ValueError at Object Creation

Add more Specific Error Message.

Related to issue #276.

Author: fschrader1992

odml/tools/xmlparser.py

@@ -314,8 +314,8 @@ def parse_tag(self, root, fmt, insert_children=True):
         obj = fmt.create()
         try:
             obj = fmt.create(**arguments)
-        except Exception as e:
-            self.error(str(e), root)
+        except ValueError:
+            self.error("ValueError: Values '%s' do not match given DType '%s'!" % (arguments['values'], arguments['dtype']), root)
 
         if insert_children:
             for child in children: