Multi-dimension rappor metrics

tools/metrics/common/models.py

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Model types for describing description xml models."""
 
 from xml.dom import minidom
 
 import sys
 import os
@@ skipping 140 matching lines @@
       else:
         obj[child.attr] = child.node_type.Unmarshall(nodes[0])
     return obj
 
   def Marshall(self, doc, obj):
     node = doc.createElement(self.tag)
     attributes = (self.int_attributes +
                   self.float_attributes +
                   self.string_attributes)
     for attr in attributes:
-      node.setAttribute(attr, str(obj[attr]))
+      if obj[attr]:
+        node.setAttribute(attr, str(obj[attr]))
 
     PutComments(node, obj['comments'])
 
     for child in self.children:
       if child.multiple:
         for o in obj[child.attr]:
           node.appendChild(child.node_type.Marshall(doc, o))
       else:
         node.appendChild(child.node_type.Marshall(doc, obj[child.attr]))
     return node
@@ skipping 33 matching lines @@
 
   def ToXML(self, comments, obj):
     doc = minidom.Document()
     for comment in comments:
       doc.appendChild(comment)
     doc.appendChild(self.root_type.Marshall(doc, obj))
     return doc
 
   def PrettyPrint(self, comments, obj):
     return self.GetPrintStyle().PrettyPrintNode(self.ToXML(comments, obj))