Merge pull request #8 from iirob/master

Extended Node.set_value() to receive ua.DataValue objects directly.

.gitignore

@@ -4,3 +4,5 @@ MANIFEST
 htmlcov*
 _*
 docs/_*
+
+*.pyc

opcua/node.py

@@ -172,12 +172,14 @@ class Node(object):
         Set value of a node. Only variables(properties) have values.
         An exception will be generated for other node types.
         """
-        variant = None
-        if isinstance(value, ua.Variant):
-            variant = value
+        datavalue = None
+        if isinstance(value, ua.DataValue):
+            datavalue = value
+        elif isinstance(value, ua.Variant):
+            datavalue = ua.DataValue(value)
         else:
-            variant = ua.Variant(value, varianttype)
-        self.set_attribute(ua.AttributeIds.Value, ua.DataValue(variant))
+            datavalue = ua.DataValue(ua.Variant(value, varianttype))
+        self.set_attribute(ua.AttributeIds.Value, datavalue)
 
     def set_attribute(self, attributeid, datavalue):
         """