old_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  # Fix some iso3 IDs that are wrong in ne_10m_admin_0_countries_lakes.shp,
  # ne_10m_admin_1_states_provinces_lakes.shp seems ok though.
  import json
  import os
  
  file_dest = os.path.abspath(
      os.path.join(os.path.dirname(__file__), '../data/countries.json'))
  
  replacements = {
      'KOS': 'XKX',  # Kosovo
      'PN1': 'PNG',  # Papua New Guniea
      'PR1': 'PRT',  # Portugal
      'SDS': 'SSD',  # S. Sudan
      'SAH': 'ESH',  # W. Sahara
  }
  
  with open(file_dest, 'r') as f:
      topo = json.load(f)
  
  countries = topo['objects']['units']['geometries']
  for country in countries:
      cid = country['properties']['iso3']
      country['properties']['iso3'] = replacements.get(cid, cid)
  
  with open(file_dest, 'w') as f:
      json.dump(topo, f, separators=(',', ':'))  # save bytes to keep file small
  
new_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  # Fix some iso3 IDs that are wrong in ne_10m_admin_0_countries_lakes.shp,
  # ne_10m_admin_1_states_provinces_lakes.shp seems ok though.
  #
  # Not all the SU_A3 IDs match those used in the ISO_A3 standard. This script replaces non-matching IDs
  # with corresponding ISO_A3 values. For more details seeissue #12 https://github.com/yaph/d3-geomap/issues/12.
  import json
  import os
  
  file_dest = os.path.abspath(
      os.path.join(os.path.dirname(__file__), '../data/countries.json'))
  
  replacements = {
      'KOS': 'XKX',  # Kosovo
      'PN1': 'PNG',  # Papua New Guniea
      'PR1': 'PRT',  # Portugal
      'SDS': 'SSD',  # S. Sudan
      'SAH': 'ESH',  # W. Sahara
  }
  
  with open(file_dest, 'r') as f:
      topo = json.load(f)
  
  countries = topo['objects']['units']['geometries']
  for country in countries:
      cid = country['properties']['iso3']
      country['properties']['iso3'] = replacements.get(cid, cid)
  
  with open(file_dest, 'w') as f:
      json.dump(topo, f, separators=(',', ':'))  # save bytes to keep file small
  
subject: Add more details about issue being fixed