code: def filter_ambiguity(records, percent=0.5):  # , repeats=6)
      
      seqs = []
      # Ns = ''.join(['N' for _ in range(repeats)])
      count = 0
      for record in records:
          if record.seq.count('N')/float(len(record)) < percent:
  #            pos = record.seq.find(Ns)
  #            if pos >= 0:
  #                record.seq = Seq(str(record.seq)[:pos])
              seqs.append(record)
          count += 1
  
      return seqs, count
docs: Filters out sequences with too much ambiguity as defined by the method
      parameters.
  
      :type records: list
      :param records: A list of sequences
      :type repeats: int
      :param repeats: Defines the number of repeated N that trigger truncating a
                      sequence.
      :type percent: float
      :param percent: Defines the overall percentage of N in a sequence that
                       will cause the sequence to be filtered out.