code: def dashes_cleanup(records, prune_chars='.:?~'):
      
      logging.info(
          "Applying _dashes_cleanup: converting any of '{}' to '-'.".format(prune_chars))
      translation_table = {ord(c): '-' for c in prune_chars}
      for record in records:
          record.seq = Seq(str(record.seq).translate(translation_table),
                           record.seq.alphabet)
          yield record
docs: Take an alignment and convert any undesirable characters such as ? or ~ to
      -.