Python - Finding a motif - input: a txt file with 10 sequences and 10 motifs

Question

When I run my BruteForce function with only one input it works and the result is correct.

def BruteForce(s, t):
    occurrences = []
    for i in range(len(s)-len(t)+1): # loop over alignment
        match = True
        for j in range(len(t)): # loop over characters
            if s[i+j] != t[j]:  # compare characters
                match = False   # mismatch
                break
        if match:   # allchars matched
            occurrences.append(i)

    print(occurrences) 

t = 'CAACTTCCA'

s = 'GACAACTTCCAACTTCCAACTTCCCGTCCCAACTTCACAACTTCGGCCCAACTTCCATGCAACTTCACCATCAACTTCGCTCGAAGCTGCCTTCCACTCCAACTTCACAACTTCCTCAACTTCCTCACCAACTTCAGCAACTTCTCTAGGGCCAACTTCCAACTTCTCAACTTCTCAACTTCCAACTTCCGACAACTTCTCCTGGCAACTTCCAACTTCCAACTTCAATACAACTTCGCAGACAACTTCCGCAACTTCGAACAACTTCCAACTTCCCCAACTTCCAACTTCCAACTTCGCCAACTTCCAACTTCCAACTTCCCAACTTCAGATAGCAACTTCGATCTTACACAACTTCACGCAACTTCTCCAACTTCCAACTTCTGTGCAACTTCTCTGAACAACTTCCTCAACTTCCAACTTCGCAACTTCCCCAACTTCCTCAACTTCATGCAACTTCGAGGCAACTTCCCAACTTCGCAACTTCCTATTCCCAACTTCTGTGGCAACTTCTCAACTTCTGGACAACTTCTATGCCCAACTTCACAACTTCCCCAACTTCTTTACAACTTCGACAACTTCATCAACTTCTAGTCAACTTCTGGTCCAACTTCCAACTTCCCCAACTTCCAAAGTGCCGCAACTTCGTAACAACTTCACGCGCTCAACTTCAACCAACTTCTTTTCCCGCAACTTCGCAACTTCACAACTTCTAATCAACTTCCAACTTCGGATCAACTTCCAACTTCGCCAACTTCCAACTTCCAACTTCTCCAGGGACAACTTCAAGTACAACTTCCAACTTCGCAACTTCACAACTTCCCAACTTCGCAACTTCTACACGCAACTTCCAACTTCTGGTCCCAACTTCATCAACTTCAGTCAACTTC'

BruteForce(s, t)

[2, 9, 48, 152, 175, 205, 212, 261, 277, 284, 300, 307, 370, 410, 607, 623, 717, 735, 751, 758, 792, 844]

But when I use it in the following loop it returns nothing! I have used the print() to see if it reads the strings and motifs from the input_2.txt file and it does but it returns an empty list of occurrences [].

with open('input_2.txt', 'r') as input_2:
    nt = input_2.readline() #nt is the no of strings+motifs in 1st line
    nt = int(nt) #in this case it is 10

    for i in range(nt):
        s = input_2.readline()
        print(s)
        t = input_2.readline()
        print(t)
        BruteForce(s, t)

Could you please let me know what changes are needed here? Many thanks, Beeta

input_2.txt:

10

GACAACTTCCAACTTCCAACTTCCCGTCCCAACTTCACAACTTCGGCCCAACTTCCATGCAACTTCACCATCAACTTCGCTCGAAGCTGCCTTCCACTCCAACTTCACAACTTCCTCAACTTCCTCACCAACTTCAGCAACTTCTCTAGGGCCAACTTCCAACTTCTCAACTTCTCAACTTCCAACTTCCGACAACTTCTCCTGGCAACTTCCAACTTCCAACTTCAATACAACTTCGCAGACAACTTCCGCAACTTCGAACAACTTCCAACTTCCCCAACTTCCAACTTCCAACTTCGCCAACTTCCAACTTCCAACTTCCCAACTTCAGATAGCAACTTCGATCTTACACAACTTCACGCAACTTCTCCAACTTCCAACTTCTGTGCAACTTCTCTGAACAACTTCCTCAACTTCCAACTTCGCAACTTCCCCAACTTCCTCAACTTCATGCAACTTCGAGGCAACTTCCCAACTTCGCAACTTCCTATTCCCAACTTCTGTGGCAACTTCTCAACTTCTGGACAACTTCTATGCCCAACTTCACAACTTCCCCAACTTCTTTACAACTTCGACAACTTCATCAACTTCTAGTCAACTTCTGGTCCAACTTCCAACTTCCCCAACTTCCAAAGTGCCGCAACTTCGTAACAACTTCACGCGCTCAACTTCAACCAACTTCTTTTCCCGCAACTTCGCAACTTCACAACTTCTAATCAACTTCCAACTTCGGATCAACTTCCAACTTCGCCAACTTCCAACTTCCAACTTCTCCAGGGACAACTTCAAGTACAACTTCCAACTTCGCAACTTCACAACTTCCCAACTTCGCAACTTCTACACGCAACTTCCAACTTCTGGTCCCAACTTCATCAACTTCAGTCAACTTC

CAACTTCCA

ATTGTGTATCGCTATGTATCGTGTATCGGATTTTGTATCGTGTATCGGTGTATCGTGTATCGTGTATCGTATCACTGTATCGTTGTATCGTAGCGTTGTATCGTAATGTATCGCTCTGTATCGTGTATCGGGTTTGTATCGATGTGTATCGCTGTATCGGTGTATCGGTGTATCGCTTGTATCGACAGCGCTTGTATCGTGTATCGACCTGTATCGGTGTATCGTGTATCGAATGTATCGTTGTATCGAATTGTGTATCGTGTATCGTGTATCGTGTATCGTATGTATCGACTGTATCGCTGTATCGTAGCCTGTATCGTGTATCGGTGTATCGGTGTATCGGCGTGTATCGAATGTATCGTTGTATCGCTGTATCGTGTGCTGTGTATCGGTGTATCGACCCGTTGTATCGTGTATCGTGGGTAAGTGTATCGTTGTATCGTAGTGTATCGTGTATCGTGTATCGTCATGGTATTGTATCGTTATAGCTGTATCGCTCGGCTGTATCGTATGTATCGTGTATCGTGTATCGCATGTATCGGTGTATCGCTGTATCGACCATGTATCGTGTATCGGTGTATCGATGTATCGCTTCCATTAGAAATGTATCGTATGTATCGTGTATCGCTGTATCGTTTGTATCGCATGTATCGATTGTGTATCGTGTATCGTTGTATCGTGTATCGTGTATCGTTGTATCGTAATAACGATGTATCGAATGATGTATCGTTGTGATGTATCGTGTATCGACTGTATCGATGTATCGGGTTGTATCGTGTATCGTGTATCGTAGATGTATCGAGAGCCATTGTATCGCCTTGTATCGCGTGTATCGGTGTGTATCGTTTGTATCGTGTTTGAATGTATCGCTGTATCG

TGTATCGTG

TTTCAGCGTGTTTGGCTTTCAGCACTACTTTCAGCGGTTTCAGCTTTTTCAGCTTTTCAGCTATTTTCAGCTTTCAGCCATCTTTCAGCCCAGGTTTCAGCTGTTTCAGCTTTCAGCGAGTTTCAGCTTTCAGCGCGGGGATTTCAGCGTATTTCAGCGACATTTCAGCAGTTTCAGCTGGAGTGAAGCCGTTTCAGCGCTTTTCAGCACCATTTCAGCTAGTAGGTTTCAGCTTTTCAGCCTTTTCAGCTTTCAGCTATTTCAGCTCTAGAAGTCGTTTCAGCTTTCAGCTTCCTTTTCAGCTTTCAGCTTTCAGCCTTTCAGCTTTCAGCAAACTTTCAGCGATTTCAGCTTTCAGCTTTCAGCTTTCAGCTTTCAGCATTTCAGCTTTCAGCCGTTTTCAGCGACTCTTTCAGCGTTTCAGCTTTCAGCTGATCGTTTTCAGCTTTTCAGCCGGTTTCAGCGAAAGTTGGTCTTTTCAGCCAAATTTTCAGCTTTCAGCTTTCAGCGTTTCAGCTTTTCAGCCATTTCAGCCTATTTTCAGCAATCTTTCAGCAATTTTCAGCGCAATTTCAGCCAAAATTTCAGCATTTCAGCTTTCAGCGTAGTTTCAGCTTTCAGCTGAGCCTTTCAGCTTTTCAGCTCTCTTTTCAGCTTTCAGCGATTTCAGCCTTTTCAGCGCTTTCAGCACCACGCCTTTCAGCTTTCAGCTTTTCAGCCTTTCAGCCTATTTTCAGCGGTTTCAGCGTTTCAGCTTTCAGCACTTTCAGCTTTCAGCTTTTCAGCGGAAGGTTTTCAGCA

TTTCAGCTT

AGCATCCGACTGCATCCGTGCATCCGACGGCATCCGGCATCCGCAGCATCCGCACAGCCGCATCCGAGCCCGCATCCGAAGCATCCGGCATCCGGGCATCCGGCCGCATCCGGCATCCGGGCATCCGTGCATCCGGCATCCGTGTGCATCCGGCATCCGGGGTGCTTGCATCCGCGCATCCGTGCATCCGCGCATCCGGCATCCGCAGTCCGCATCCGCGCATCCGGCATCCGAGCATCCGTATTCGCATCCGTCGAGCATCCGTACGTCGCATCCGTGCATCCGGGAGAGGCATCCGGGCATCCGCGCATCCGGTGGACTATAACGCGCATCCGGCGAGCATCCGCCGCGGCATCCGTGCATCCGGTACGGCATCCGGGCTGAGGCATCCGCTCCCGGGGCATCCGCGGCGCATCCGCACGCGCATCCGGCATCCGAGCATCCGTTGCATCCGGAGCATCCGTAGCATCCGATAGCATCCGCAAGCTTGCATCCGGCATCCGCTACAGCATCCGGTGGCATCCGAAGCATCCGCGCATCCGCGGATTGCATCCGCACACGGCATCCGTAGCATCCGTGCATCCGGAGTGCATCCGCCGGGCGCATCCGCTGCATCCGCAGCGCATCCGAGCATCCGATCTTGCATCCGGCATCCGGGAATGCATCCGGGACTGCATCCGGTCTTAAGGGTGCATCCGAATGCATCCGCTGTAGCATCCGGCATCCGAGTAAGCATCCGAGTTCTGCATCCGGAAGCAGCATCCGGCATCCGGACACCAGCATCCGCGCATCCGGGGCGAGCATCCGAGCATCCGGCATCCGGGGCAAGTGGCATCCGGCATCCGTCGTGCATCCGGGCATCCGAA

GCATCCGGC

GACGAGCTGACGAGCGTGACGAGCAGGCGACGAGCGACGAGCATGCGGTGACGAGCGGACGAGCGACGACGAGCGCGGACGAGCGACGAGCGGACGAGCTCCGACGAGCGACGAGCACGACGAGCGCCCGACGAGCGACGAGCATGATGACGAGCGACGAGCTTAGACGAGCATGCTGACGAGCTGACGAGCTGACGAGCTCGTACATCGACGAGCGGACGAGCAGCCCGATAAGCCTTCGACGAGCTGACGAGCCACGACGAGCGACGAGCGACGAGCGGACGAGCGGGACGAGCGTCGGACGAGCGGACGAGCAGGACGAGCACCTCAATCGACGAGCTGACGAGCGGACGAGCCGACGAGCTGAACTGAAGGACGAGCCTACGTTCTAACGTGCCGTCACTGACGAGCGACGAGCGGACGAGCGATGGACGAGCTGACGAGCGCAGGACGAGCGAGAAGGCTGACGAGCAGACGAGCTGACGAGCTCGACGAGCAGACGAGCGGACGAGCTTTGATAAGACGAGCACGTCGACGAGCCTCGTGACGAGCTGACGAGCGACGAGCTAGACGAGCGACGAGCTGACGAGCGACGAGCACTAAACGCGACGAGCTCGACGACGAGCATGGACGAGCGACGAGCTAGGACGAGCGGCGACGAGCAGACGAGCGACGAGCTGACGAGCTTATAGACGAGCCTGACGACGAGCCAAGACGAGCGACGAGCGGACGAGCGACGAGCACGACGAGCCGACGAGCCGCGGACGAGCCGTAGACGAGCCAATCATTAAGACGAGCCGACGAGCCATTTGGGGACGAGCCTCCTCGACGAGCCATAAGACGAGCTGACGAGCCATGACGAGCATGCCCGACGAGC

GACGAGCGA

GAGGACCCCGGACCCCTGGACCCCAGGACCCCGACGGTGGGGCGGACCCCGAGAAGGACCCCTGGACCCCCGCAGGACCCCTTTATCGGACCCCGGACCCCGGACCCCCGGACCCCGGCTGGACCCCGTCGTAAGGACCCCGAATCGGACCCCTAGGACCCCAGGGACCCCTCCCCGGTTGGACCCCCTGGACCCCCTTGAGAGGGACCCCGGACCCCACGCCGTGCTTAAGGACCCCACTATGGACCCCATACGGACCCCGGACCCCGATCAGAGCGACCAGGACCCCCGGCCTGGACCCCTCGGACCCCAGAAGGACCCCTCGGACCCCTGGACCCCGGACCCCACAGGGACCCCGGACCCCTAGCCGCGGTGGACCCCCGGACCCCCGCAGATGGGGACCCCTCATGCGGACCCCCTGACGGACCCCTGGACCCCCGGGACCCCCAGGGACCCCATTTCGAGGACCCCATGGGGACCCCAAGCTGGACCCCGGACCCCTGGGACCCCCGGACCCCGGACCCCGGACCCCATAGGACCCCCGTTTGTTGCCATGGACCCCTTGGGACCCCGAGTCGGACCCCGGACCCCCAGGACCCCACAGGACCCCGGGACCCCGGACCCCATCGATCGGACCCCGGACCCCGGACCCCTACGGACCCCGCTAAGGGACCCCGGACCCCGTGGACCCCCACGGACCCCTAGGACCCCGGGACCCCGGACCCCGGACCCCAGTTGGACCCCCCTTAGGACCCCAGGACCCCACATGAGGACCCCGGGACCCCGGGACCCCTGGACCCCTGGACCCC

GGACCCCGG

AAACCTTCGGACCTTCGTACCTTCGACCTTCGTGAAACCTTCGGACCTTCGTGACCTTCGGGTGACCTTCGGGTACTCACCTTCGGCACCTTCGTATACCTTCGAGACCTTCGCTGGACTGTAAACCTTCGATCGTTATTTTCTACCTTCGCACACCTTCGACCTTCGAGCCGAACCTTCGGACTGGCCTCACCTTCGATCACCTTCGACCTTCGAACCTTCGACCTTCGACCATACCTTCGACCTTCGGACCTTCGGACCTTCGCACCTTCGAACCTTCGCCACCTTCGACCTTCGAACCTTCGGTGGGCCACCTTCGTTACCTTCGAACCTTCGGGCACCTTCGACCTTCGGCTTACACCTTCGGACCTTCGATGACTGACCTTCGAAACCTTCGACCTTCGACCTTCGATTCCACACCTTCGACCTTCGACACCTTCGACCTTCGCGTTCACCTTCGACCTTCGACCTTCGGGCCAATACCTTCGACCTTCGGCCTAATACCAACCTTCGAACCTTCGAACCTTCGGGTGACCTTCGGACCTTCGCGCACACCTTCGCACTTACCTTCGACCTTCGGTGACCTTCGACCTTCGTGCACCTTCGCGTCTCACCTTCGCACCTTCGTTACCTTCGAACCTTCGACCTTCGACAACCTTCGTACCTTCGCTACCTTCGGGAACCTTCGATGTCCTACCTTCGACCTTCGCGACCTTCGACCTTCGTAACCTTCGAACCTTCGACCACCTTCGAACCTTCGAAGGAAGGACCTTCGAATCATTACCTTCGTTACCTTCGTAGTACCTTCGCCGACCTTCGGACCTTAACCTTCGTGA

ACCTTCGAC

AAGTGGTATTCCCAAAAAGATATTCCCGTTATTCCCGCTATAAATATTCCCAACTGTTTATTCCCACTTATTCCCGTATTCCCGTATTCCCCGGGCCTTTTATTCCCCATTCTATTCCCGTATTCCCATATTCCCACTTATTCCCCTATTCCCATATTCCCTATTCCCTATTCCCGTAAGTATTCCCCCCCTTATTCCCCCATTTGTCCATATTCCCTCAATATTCCCTATTCCCCTATTCCCGCTTCCCCAGTCTATCCCAAATTGTATTCCCAATATTCCCCTTTATTCCCTTTATTCCCGTATTCCCTATTCCCGTGGCTATTCCCCCGACGTTATTCCCTCTATATTCCCGTCTCAAAGTATTCCCTTATTCCCAGTATTCCCATTCGCCTGGTATTCCCGTATTCCCGGTATTCCCGTTTATTCCCATCTATTCCCATTATTCCCTGGTATTCCCGCTATTCCCGCAACGGTATTCCCTATTCCCTATTCCCGTATTCCCAATATTCCCTTCCTATTCCCGTATTCCCTAGCTATTCCCATATTCCCGATATTCCCTATTCCCGTATTCCCTATTCCCTTATTCCCTATTCCCTAGTTATTCCCAAACAGGCTATTCCCTATTCCCTATTCCCATATTCCCTTATTCCCTACGTATTCCCTCTTAAAAATATTATTCCCCTATTCCCTATTCCCGTATTCCCCGAAAGTATTCCCCCATATTCCCAATTATATTCCCGGTATTCCCCCGTATTCCCTATTCCCTTATTCCCATATTCCCATATTCCCAAAGTTTATTCCCGTATTCCCCACTATTCCCATAGATTATTCCCTATTCCCTATTCCCTTATTCCCCTATTCCCTATTCCCTTATTCCCGTATTCCCAGTTTATTCCC

TATTCCCTA

GAAAGGATAAAGGATGTCAAAGGATGCAGATATAAAGGATAAAGGATACAAAGGATTAAGTATGTCCGAAAAAGGATAAAGGATTAAAAGGATCGCTGAACCTTACACAAAGGATAGTGAACAAAGGATTCAATAAAAGGATAAAGGATCAAAGGATCAAAAGGATACAAAGGATGCCGATGAAAGGATAAAGGATCTAAAGGATAAAGGATGAGAAAGGATTGGAAAGGATTATGAGATCAAAGGATAAAGGATGGTGTAAAAGCTAAAGGATTCGGCAAAGGATAAAGGATTAAAGGATAAAAAGGATAAAGGATGAAAGGATCCGCAGGGACCAGCAAAAGGATAAAGGATCGAATGGGTAAGAAAGGATCAAAGGATGAAAAAGGATTACTAAAGGATAAAGGATCCTGAAAGGATTACAAAGGATCTTAAAAGGATTCGGAAAGGATCCATAGGAAAAGGATAAAGGATCGCGAAAGGATAAAGGATTAAAGGATAAAGGATAAAAGGATTCAAAGGATAAAGGATAGACAAGGGAGAAAGGATGCAAAGGATGAAAGGATAAAGGATAAAGGATAAAGGATTAGGTTAAAGGATCGAAAGGATCCAAAGAGAGCGAAAAGGATGAGGACGAAAGGATCAAAGGATCCAAAGGATCAAAGGATAAAGGATTGCGATGGAAAGGATGTCAAAGGATCACCAAAGGATAAAGGATAATAAAGGATAAAGGATAAAGGATCAAAGGATTTGAAAAGGATAAAGGATCACGAAAGGATAAAAGGATTGGCAAAGGATGAAAAGGATGAAAGGATAAGCCCTCCAAAGGAT

AAAGGATAA

ATTCAAATACTTCAAATAGTCAAATATCAAATATGCTTCAAATATCAAATATCGGTCAAATAAGTCAAATAAGTCAAATATCAAATATCAAATACTCAAATATCAAATAGTGTCAAATACGAATTGGGTCAAATATCAAATATGTGTTCAAATATTCTTCAAATACTGGACACTCAAATAGGAGTCAAATATCAAATATCAAATACGTGAAGTGCTTGTCAAATATTTCAAATACTTTCAAATATTCAAATACTCAAATATGTTCAAATATCAAATATCAAATATTTCAAATATCAAATATCAAATAGTCCTCAAATAGCAAACCAGTCAAATATCAAATATGTCAAATATGCTCACGGCAACCTCAAATATCAAATATCAAATAGATGTCAAATAAGTTTCAAATATCAAATATCAAATATCAAATATCAAATATTCAAATATCAAATAGCGGGCTCAAATAAGCTCAAATACGTCAAATAGGGGGTCAAATAGATCAAATAGTCAAATATTCAAATACATCAAATAGTCAAATACAAGAACCACCGAGATCTCAAATAATCAAATATCAAATATGGTCAAATAAATATTCAAATAGGTCAAATAAGATCAAATATCAAATAAGTCGTCCATCAAATAGTCAAATAGCTCAAATAACCTCAAATATCAAATATTCAAATACCGGTCATCAAATAGGACAAATCAAATAGTCAAATAAGATCCTCTCAAATAATTCAAATAGCTGTTCAAATACTCAAATATCAAATAGTCAAATATCAAATATTCAAATATCAAATACTTCAAATATGTTCAAATAATCAAATACTCAAATATCAAATAATCAAATAATACTTCAAATATACCAAACGCTCAAATATTAGTTGGATCAAATATCTTCAAATATCAAATAA

TCAAATATC

Answer 1

Let's start by doing some explaining about why your code doesn't work.

with open('input_2.txt', 'r') as input_2:
    nt = input_2.readline() #This is reading the first line of the file (which is 10)
    nt = int(nt) # this is storing "10" as an int

    for i in range(nt): # This is the same as "for i in range(10):" which just returns nums 0-9, does not access lines of your file
        s = input_2.readline() # this is reading the second line which is blank 
        print(s) # this will print a blank line 10 blank lines
        t = input_2.readline() # this is reading the rest of the file
        print(t)
        BruteForce(s, t) # this is calling your function on 10 blank lines and the restof your file, not each seq/motif

I made some modifications that will help you achieve your goal I think:

def BruteForce(s, t):
    occurrences = []
    for i in range(len(s)-len(t)+1): # loop over alignment
        match = True
        for j in range(len(t)): # loop over characters
            if s[i+j] != t[j]:  # compare characters
                match = False   # mismatch
                break
        if match:   # allchars matched
            occurrences.append(i)

    print(occurrences)

def group(lst, n):
    """ This function will be used to group your sequences and motifs later """
    for i in range(0, len(lst), n):
        val = lst[i:i+n]
        if len(val) == n:
            yield tuple(val)

with open('input_2.txt') as input_2: #standard open in read mode, 
    lines = input_2.readlines()[2:] # skip 10 and the blank space bc we don't care about them
    split_line = [line.strip('\n') for line in lines if line!='\n'] #this will store lines that aren't blank into a list and strip new_line chars '\n'
    seq_tuple = list(group(split_line, 2)) # this will use group func above to group the list into tuples of 2's which are sequence and motif.

for x in seq_tuple: # this accesses the list of tuples (seq_tuple)
    BruteForce(x[0], x[1]) # x[0] in each tuple is seq, or BruteForce(s), x[1] in each tuple is motif, or BruteForce(t)

Running this will output Each motifs start position in each sequence:

[2, 9, 48, 152, 175, 205, 212, 261, 277, 284, 300, 307, 370, 410, 607, 623, 717, 735, 
751, 758, 792, 844]
[14, 33, 48, 55, 116, 192, 217, 253, 260, 267, 312, 370, 405, 412, 445, 452, 511, 
518, 561, 613, 657, 672, 679, 735, 769, 776, 847]
[37, 46, 64, 103, 120, 226, 243, 277, 284, 296, 303, 318, 345, 352, 359, 366, 381, 418, 439, 488, 495, 510, 590, 608, 628, 648, 697, 704, 748, 764, 771]
[29, 80, 95, 105, 128, 145, 191, 219, 328, 423, 489, 642, 713, 758, 808, 831]
[28, 57, 77, 102, 129, 148, 258, 265, 404, 419, 449, 553, 569, 584, 629, 664, 713, 728]
[2, 87, 94, 109, 204, 254, 332, 350, 487, 511, 518, 577, 603, 611]
[18, 154, 201, 216, 223, 235, 283, 339, 390, 397, 418, 425, 434, 453, 460, 481, 565, 582, 637, 644, 695, 711, 735]
[154, 161, 221, 303, 476, 483, 526, 554, 569, 584, 591, 617, 624, 647, 685, 754, 829, 836, 859]
[1, 33, 70, 135, 182, 198, 241, 279, 294, 303, 340, 395, 460, 478, 493, 500, 517, 559, 566, 573, 661, 704, 711, 721, 728, 754, 772, 808]
[19, 37, 44, 73, 80, 95, 128, 184, 191, 263, 270, 286, 293, 327, 364, 371, 400, 407, 414, 421, 436, 561, 609, 659, 754, 769, 784, 826, 886, 896]

Answer 2

This looks hard work. In Perl the function "index" and "rindex" as well as "substr" will perform this without the incremental loop. There must be an equivalent in Python?

I've not tried this, but at a guess it would be something like,

my @array;
my $target = 'AGATAGAGAGATAGAGAGATAGAGAGATAGAGAGATAGAG';
my $query = 'AGAGA';
while(length($target) > 4){
    my $location = index ($query, $target);
    push @array, $location;
    $target = substr ($location, length($target), $target);
}
print join("\s", @array), "\n";