CodeAcademy Python project: DNA Analysis

dna.py

sample = ['GTA','GGG','CAC']

def read_dna(dna_file):
  dna_data = ""
  with open(dna_file, "r") as f:
    for line in f:
      dna_data += line
  return dna_data

def dna_codons(dna):
  codons = []
  for i in range(0, len(dna), 3):
    if (i + 3) < len(dna):
      codons.append(dna[i:(i + 3)])
  return codons

def match_dna(dna):
  matches = 0
  for codon in dna:
    if codon in sample:
      matches += 1
  return matches

def is_criminal(dna_sample):
  dna_data = read_dna(dna_sample)
  codons = dna_codons(dna_data)
  num_matches = match_dna(codons)
  if num_matches >= 3:
    print("There were %d codon matches in %s. Further investigation should be done") %(num_matches, dna_sample)
  else:
    print("There were only %d codon matches in %s. As the dna test clears this suspect of any allegations they can be freed") % (num_matches, dna_sample)
    
is_criminal('suspect1.txt')
is_criminal('suspect2.txt')
is_criminal('suspect3.txt')