python3 - 2to3 + miscell obvious tweaks

[sfa.git] / sfa / rspecs / elements / element.py

diff --git a/sfa/rspecs/elements/element.py b/sfa/rspecs/elements/element.py
index 6757f8a..7dcfa00 100644 (file)
--- a/sfa/rspecs/elements/element.py
+++ b/sfa/rspecs/elements/element.py
@@ -2,8 +2,22 @@ class Element(dict):
 
     fields = {}
 
-    def __init__(self, fields={}, element=None):
+    def __init__(self, fields=None, element=None, keys=None):
+        if fields is None:
+            fields = {}
         self.element = element
-        dict.__init__(self, self.fields) 
-        self.update(fields)
+        dict.__init__(self, dict.fromkeys(self.fields))
+        if not keys:
+            keys = list(fields.keys())
+        for key in keys:
+            if key in fields:
+                self[key] = fields[key]
 
+    def __getattr__(self, name):
+        if hasattr(self.__dict__, name):
+            return getattr(self.__dict__, name)
+        elif hasattr(self.element, name):
+            return getattr(self.element, name)
+        else:
+            raise AttributeError("class Element of type {} has no attribute {}"
+                                 .format(self.__class__.__name__, name))