Objective: Write a program that counts the number of A's in a DNA sequence. The input is one sequence in FASTA format in a file called 'dna.txt'.
My input file:
>Human AGCATGCATCGATCGATCGACTAGCTAGCG >Chimp GATATGTCGAGATCGTCAGCTCGATCAGCT >Gorilla TGTGTCGATCTCGAGCTGAGTCGTCTATCA
Output: I don't need to create only print output info
My code so far:
DNA_list =  with open('dna.fasta.py') as f_in: lines = f_in.read() if lines == 'A' or 'C' or 'G' or 'T': DNA_list = DNA_list.append(lines) else: pass
What I would like to do and Issue:
After creating the list of DNA sequences/strings , for each sequence, I would like would like to count the 'A's using the count method and then I would just print to IDLE. The problem is that IDLE is saying that there is 'None' in the DNA_list. I don't know why the sequences were not appended to my list.
I have no idea what I'm doing wrong and would like to know if I'm heading in the right direction and how to fix my program.