code: def read_sheets(archive):
      
      xml_source = archive.read(ARC_WORKBOOK)
      tree = fromstring(xml_source)
      for element in safe_iterator(tree, '{%s}sheet' % SHEET_MAIN_NS):
          attrib = element.attrib
          attrib['id'] = attrib["{%s}id" % REL_NS]
          del attrib["{%s}id" % REL_NS]
          if attrib['id']:
              yield attrib
docs: Read worksheet titles and ids for a workbook