Clean up ElementTree usage

Use lxml in favor of ElementTree to
make things more consistent.

Fixes LP: #953449

Change-Id: I7f48528d7df47fe7207ca88bce196dea7535df0e
Signed-off-by: Chuck Short <chuck.short@canonical.com>

nova/tests/fakelibvirt.py

@@ -14,12 +14,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from xml.etree import ElementTree
-try:
-    ParseError = ElementTree.ParseError
-except AttributeError:
-    from xml.parsers import expat
-    ParseError = expat.ExpatError
+from lxml import etree
 
 import uuid
 
@@ -141,7 +136,7 @@ class NWFilter(object):
         self._parse_xml(xml)
 
     def _parse_xml(self, xml):
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
         root = tree.find('.')
         self._name = root.get('name')
 
@@ -163,8 +158,8 @@ class Domain(object):
 
     def _parse_definition(self, xml):
         try:
-            tree = ElementTree.fromstring(xml)
-        except ParseError:
+            tree = etree.fromstring(xml)
+        except etree.ParseError:
             raise libvirtError(VIR_ERR_XML_DETAIL, VIR_FROM_DOMAIN,
                                "Invalid XML.")
 
@@ -301,13 +296,13 @@ class Domain(object):
                 123456789L]
 
     def attachDevice(self, xml):
-        disk_info = _parse_disk_info(ElementTree.fromstring(xml))
+        disk_info = _parse_disk_info(etree.fromstring(xml))
         disk_info['_attached'] = True
         self._def['devices']['disks'] += [disk_info]
         return True
 
     def detachDevice(self, xml):
-        disk_info = _parse_disk_info(ElementTree.fromstring(xml))
+        disk_info = _parse_disk_info(etree.fromstring(xml))
         disk_info['_attached'] = True
         return disk_info in self._def['devices']['disks']
 
@@ -404,7 +399,7 @@ class Domain(object):
         self._state = VIR_DOMAIN_RUNNING
 
     def snapshotCreateXML(self, xml, flags):
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
         name = tree.find('./name').text
         snapshot = DomainSnapshot(name, self)
         self._snapshots[name] = snapshot
@@ -741,7 +736,7 @@ class Connection(object):
 </capabilities>'''
 
     def compareCPU(self, xml, flags):
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
 
         arch_node = tree.find('./arch')
         if arch_node is not None: