title: Iterating through tuples to count values in list
body: <p>I have a dictionary with multiple genes. The tuple(zip()) gives the nucleotide at each site. E.g. (A, A, A), (T, T, G), etc. I'm trying to count the number of nucleotides at each site. Such that site 1 shows 3 A's, and site 2 shows 2 T's and 1 G. When I run my code, it is only adding to A and nothing else. </p>
  
  <pre><code>List = tuple(zip(*myDict.values()))
  
  A = 0
  T = 0
  G = 0
  C = 0
  
  site = 0
  
  for value in List:
      site +=1
      if 'A':
          A += 1
      elif 'T':
          T += 1
      elif 'G':
          G += 1
      else:
          C =+ 1
  
  print 'Site:', site
  print 'A:', A
  print 'T:', T
  print 'G:', G
  print 'C:', C
  </code></pre>