#!/usr/bin/python
# Parse an OSM file and add a <tag k="name"> (if missing) to nodes
# which have the specified <tag k="tag_type"> (e.g. k="amenity").
# The tag_type value (e.g. v="restaurant") is used as the missing name.

import sys
import xml.etree.ElementTree

xml_file = sys.argv[1]
tag_type = sys.argv[2]
out_file = sys.argv[3]

tree = xml.etree.ElementTree.parse(xml_file)
for node in tree.getroot().findall(u'node'):
    tag_k_type = node.find(u"tag[@k='%s']" % (tag_type,))
    if tag_k_type != None:
        # Found node:
        # <node ...>
        #   <tag k="tag_type" v="type_value" />
        #   <tag k="name" v="name_value" />
        tag_k_name = node.find(u"tag[@k='name']")
        if tag_k_name == None:
            type_value = tag_k_type.get('v')
            tag = xml.etree.ElementTree.Element('tag', {'k': 'name', 'v': type_value})
            node.append(tag)
tree.write(out_file, encoding="utf-8", xml_declaration=True)