How to pick outer nodes by inner node content

pick-nodes.py

#!/usr/bin/env python

import xml.dom.minidom as dom
import xml

import sys

def read_xml_file( fn ):
	return dom.parse( fn ).documentElement


def pick_outer_tag_by_inner_content( nodes, outer_tag, inner_tag, predicate ):
	out = []
	
	outer_nodes = nodes.getElementsByTagName( outer_tag )
	
	for outer_node in outer_nodes:
		inner_nodes = outer_node.getElementsByTagName( inner_tag )
		for inner_node in inner_nodes:
			for node in inner_node.childNodes:
				
				if node.nodeType == node.TEXT_NODE:
					if predicate( node.data ):
						out.append( outer_node )
	return out
	
	


doc = read_xml_file( sys.argv[1] )


wanted_stuff = ["ulkomaat", "kulttuuri"]

nodes = pick_outer_tag_by_inner_content( doc, "item", "category", lambda node: node.lower() in wanted_stuff )

result = dom.getDOMImplementation().createDocument(None, "results", None )
root = result.documentElement

for node in nodes:
	root.appendChild( node )


print result.toprettyxml()