docs: def read_archive(archive, fname):
      """Return an iterator of unique rows from a zip archive.
  
      * archive - path to the zip archive.
      * fname - name of the compressed file within the archive.
  
      """
  
      # Note that deduplication here is equivalent to an upsert/ignore,
      # but avoids requirement for a database-specific implementation.
  
      zfile = zipfile.ZipFile(archive)
      contents = zfile.open(fname, 'r')
      fobj = io.TextIOWrapper(contents)
  
      seen = set()
      for line in fobj:
          line = line.rstrip('\t|\n')
          if line not in seen:
              yield line.split('\t|\t')
              seen.add(line)