silly_generator_subseq_matching

def find_subseq(seq, subseq, idx=0, end=None):
    subseq_len = len(subseq)
    while True:
        idx = seq.find(subseq, idx)
        if idx == -1:
            break
        if end is not None and idx > (end - subseq_len):
            break
        yield idx
        idx +=1

seq = 'ACAATGGGAGAGTCCATTCTACAATGGGAGAGTCCATTCT'
subseq1 = 'AC'
subseq2 = 'AT'

match1 = list(find_subseq(seq,subseq1))
match2 = list(find_subseq(seq,subseq2))
match3 = list(find_subseq(seq,subseq2, 3, 25))