code: def read_content_types(archive):
      
      xml_source = archive.read(ARC_CONTENT_TYPES)
      root = fromstring(xml_source)
      contents_root = root.findall('{%s}Override' % CONTYPES_NS)
      for type in contents_root:
          yield type.get('ContentType'), type.get('PartName')
docs: Read content types.