code: def parse_file(file):
      
      lines = []
      for line in file:
          line = line.rstrip('\n')
          if line == '%%':
              # This is a separator between items. Parse the data we've
              # collected and yield the result.
              yield from parse_item(lines)
              lines.clear()
          elif line.startswith('  '):
              # This is a continuation line. Concatenate it to the previous
              # line, including one of the spaces.
              lines[-1] += line[1:]
          else:
              lines.append(line)
      yield from parse_item(lines)
docs: Take an open file containing the IANA subtag registry, and yield a
      dictionary of information for each subtag it describes.