On Fri, Mar 2, 2012 at 2:11 PM, Hs Hs <ilhs...@yahoo.com> wrote: > Hi: > I have the following table and I am interested in calculating mismatch > ratio. I am not completely clear how to do this and any help is deeply > appreciated. > > Length Matches > 77 24A0T9T36 > 71 25^T9^T37 > 60 25^T9^T26 > 62 42A19 > > > In length column I have length of the character string. > In the second column I have the matches my reference string. > > > In fist case, where 77 is length, in matches from left to right, first 24 > matched my reference string following by a extra character A, a null (does > not account to proble) and extra T, 9 matches, extra T and 36 matches. > Totally there are 3 mismatches > > In case 2, I lost 2 characters (^ = loss of character compared to reference > sentence) - > > TOMISAGOODBOY > T^MISAGOOD^OY (here I lost 2 characters) = I have 2 mismatches > TOMISAGOOODBOOY (here I have 2 extra characters O and O) = I have two > mismatches > > > In case 4: I have 42 matches, extra A and 19 matches = so I have 1 mismatch > > > How can that mismatch number from matches string. > 1. I have to count how many A or T or G or C (believe me only these 4 > letters will appear in this, i will not see Z or B or K etc) > 2. ^T or ^A or ^G or ^C will also be a mismatch > > > desired output: > > Length Matches mismatches > 77 24A0T9T36 3 > 71 25^T9^T37 2 > 60 25^T9^T26 2 > 62 42A19 1 > 10 6^TTT1 3 >
It looks like all you need to do is count the number of A, T, C, and G characters in your Matches column. Maybe something like this: differences = [ [77, '24A0T9T36'], [71, '25^T9^T37'], [60, '25^T9^T26'], [62, '42A19'] ] for length, matches in differences: mismatches = 0 for char in matches: if char in ('A', 'T', 'G', 'C'): mismatches += 1 print length, matches, mismatches which produces the following output: 77 24A0T9T36 3 71 25^T9^T37 2 60 25^T9^T26 2 62 42A19 1 -- Jerry _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor