def maskSequences(sequences, masker=None):

    if masker in ("dust", "dustmasker"):
        masker_object = MaskerDustMasker()
    else:
        masker_object = None

    if masker == "softmask":
        # the genome sequence is repeat soft-masked
        masked_seq = sequences
    elif masker in ("dust", "dustmasker"):
        # run dust
        masked_seq = masker_object.maskSequences(
            [x.upper() for x in sequences])
    elif masker is None:
        masked_seq = [x.upper() for x in sequences]
    else:
        raise ValueError("unknown masker %s" % masker)

    # hard mask softmasked characters
    masked_seq = [re.sub("[a-z]", "N", x) for x in masked_seq]

    return masked_seq
return a list of masked sequence.
dataset/ETHPy150Open CGATOxford/cgat/CGAT/Masker.py/maskSequences