Handle default namespace in xml

gistfile1.py

from lxml import etree
from StringIO import StringIO

s = '''<?xml version="1.0" encoding="UTF-8"?>
<Environment
     xmlns="http://schemas.dmtf.org/ovf/environment/1"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns:oe="http://schemas.dmtf.org/ovf/environment/1"
     xmlns:ve="http://www.vmware.com/schema/ovfenv"
     oe:id=""
     ve:vCenterId="vm-61">
   <PlatformSection>
      <Kind>VMware ESXi</Kind>
      <Version>5.5.0</Version>
      <Vendor>VMware, Inc.</Vendor>
      <Locale>en</Locale>
   </PlatformSection>
   <PropertySection>
         <Property oe:key="ppEnv" oe:value="production"/>
         <Property oe:key="pphostname" oe:value="coolhostname"/>
   </PropertySection>
   <ve:EthernetAdapterSection>
      <ve:Adapter ve:mac="00:50:56:94:9a:56" ve:network="Service" ve:unitNumber="7"/>
   </ve:EthernetAdapterSection>
</Environment>'''

f = StringIO(s)
tree = etree.parse(f)
oe = '{http://schemas.dmtf.org/ovf/environment/1}'

namespaces={'oe': 'http://schemas.dmtf.org/ovf/environment/1', 'xsi': 'http://www.w3.org/2001/XMLSchema-instance', 've': 'http://www.vmware.com/schema/ovfenv'}
print tree.xpath('//oe:Property', namespaces=namespaces)
#output [<Element {http://schemas.dmtf.org/ovf/environment/1}Property at 0xf936f88>, <Element {http://schemas.dmtf.org/ovf/environment/1}Property at 0xf941088>]


print tree.xpath('//oe:Property[@oe:key="pphostname"]/@oe:value', namespaces=namespaces)
#output ['coolhostname']