Saving XML files using ElementTree

Question

I'm trying to develop simple Python (3.2) code to read XML files, do some corrections and store them back. However, during the storage step ElementTree adds this namespace nomenclature. For example:

<ns0:trk>   <ns0:name>ACTIVE LOG</ns0:name> <ns0:trkseg> <ns0:trkpt lat="38.5" lon="-120.2">   <ns0:ele>6.385864</ns0:ele>   <ns0:time>2011-12-10T17:46:30Z</ns0:time> </ns0:trkpt> <ns0:trkpt lat="40.7" lon="-120.95">   <ns0:ele>5.905273</ns0:ele>   <ns0:time>2011-12-10T17:46:51Z</ns0:time> </ns0:trkpt> <ns0:trkpt lat="43.252" lon="-126.453">   <ns0:ele>7.347168</ns0:ele>   <ns0:time>2011-12-10T17:52:28Z</ns0:time> </ns0:trkpt> </ns0:trkseg> </ns0:trk> 

The code snippet is below:

def parse_gpx_data(gpxdata, tzname=None, npoints=None, filter_window=None,                    output_file_name=None):         ET = load_xml_library();      def find_trksegs_or_route(etree, ns):         trksegs=etree.findall('.//'+ns+'trkseg')         if trksegs:             return trksegs, "trkpt"         else: # try to display route if track is missing             rte=etree.findall('.//'+ns+'rte')             return rte, "rtept"      # try GPX10 namespace first     try:         element = ET.XML(gpxdata)     except ET.ParseError as v:         row, column = v.position         print ("error on row %d, column %d:%d" % row, column, v)      print ("%s" % ET.tostring(element))     trksegs,pttag=find_trksegs_or_route(element, GPX10)     NS=GPX10     if not trksegs: # try GPX11 namespace otherwise         trksegs,pttag=find_trksegs_or_route(element, GPX11)         NS=GPX11     if not trksegs: # try without any namespace         trksegs,pttag=find_trksegs_or_route(element, "")         NS=""      # Store the results if requested     if output_file_name:         ET.register_namespace('', GPX11)         ET.register_namespace('', GPX10)         ET.ElementTree(element).write(output_file_name, xml_declaration=True)      return; 

I have tried using the register_namespace, but with no positive result. Are there any specific changes for this version of ElementTree 1.3?

Answer 1

In order to avoid the ns0 prefix the default namespace should be set before reading the XML data.

ET.register_namespace('', "http://www.topografix.com/GPX/1/1") ET.register_namespace('', "http://www.topografix.com/GPX/1/0") 

Answer 2

You need to register all your namespaces before you parse xml file.

For example: If you have your input xml like this and Capabilities is the root of your Element tree.

<Capabilities xmlns="http://www.opengis.net/wmts/1.0"     xmlns:ows="http://www.opengis.net/ows/1.1"     xmlns:xlink="http://www.w3.org/1999/xlink"     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"     xmlns:gml="http://www.opengis.net/gml"     xsi:schemaLocation="http://www.opengis.net/wmts/1.0 http://schemas.opengis.net/wmts/1.0/wmtsGetCapabilities_response.xsd"     version="1.0.0"> 

Then you have to register all the namespaces i.e attributes present with xmlns like this:

ET.register_namespace('', "http://www.opengis.net/wmts/1.0") ET.register_namespace('ows', "http://www.opengis.net/ows/1.1") ET.register_namespace('xlink', "http://www.w3.org/1999/xlink") ET.register_namespace('xsi', "http://www.w3.org/2001/XMLSchema-instance") ET.register_namespace('gml', "http://www.opengis.net/gml")