def make_kmers(seq, K):
    seq = str(seq).upper().replace('N', 'A')
    seqlen = len(seq)
    for i in range(((seqlen - K) + 1)):
        (yield seq[i:(i + K)])
def make_kmers(seq, K):
    seq = str(seq).upper().replace('N', 'A')
    seqlen = len(seq)
    for i in range(((seqlen - K) + 1)):
        (yield seq[i:(i + K)])