XML : write the whole content of xml node without adding "xmlns="

From my xml file, I want to write each child node to a separate file. I use xml.etree.ElementTree.tostring(child_node) for this. I already found that I should use .register_namespace() to avoid adding "ns0:" to every tag. But I still have "xmlns=" attribute added to every node I am saving:

Here is sample xml file:

  <?xml version="1.0" encoding="UTF-8"?>  <kml xmlns="http://earth.google.com/kml/2.1">  <Document>   <name>ref.kml</name>   <Style id="normalState">      <IconStyle><scale>1.0</scale><Icon><href>yt.png</href></Icon></IconStyle>      <BalloonStyle><text><![CDATA[$[description]]]></text></BalloonStyle>       </Style>  </Document>  </kml>    

Here is my code:

  #!/usr/bin/env python    import xml.etree.ElementTree as ET    str_ns_url = 'http://earth.google.com/kml/2.1'  ET.register_namespace('', str_ns_url)    kml_file = ET.parse('my.kml')  kml_doc = kml_file.getroot()[0]    ndx = 0  for child in kml_doc:      ndx+=1      f = open('node'+str(ndx)+'.txt','w')      f.write(ET.tostring(child))      f.close()    

And this is the output for the first node (<name>):

  <name xmlns="http://earth.google.com/kml/2.1">ref.kml</name>    

As you see, xmlns= was added to the tag. So far I only found this SO post which basically suggests manual removal of that substring after .tostring(). Is there any better solution? Maybe I should use something else instead of ElementTree.tostring()?