title: python3 sum in stings each letter value
body: <p>i need sum in string letters value ex.
      a = 1
      b = 2
      c = 3
      d = 4</p>
  
  <pre><code>alphabet = 'abcdefghijklmnopqrstuvwxyz'
  
  v1
  
  string = "abcd"
  
  # #result = sum(string) so 
  if string[0] and string[1] and string[2] and string[3] in alphabet:
     if string[0] is alphabet[0] and string[1] is alphabet[1] and string[2] is alphabet[2] and string[3] is alphabet[3]:
        print(a+b+c+d)
  
  v2
  
  string = ("ab","aa","dc",)
  
  if string[0][0] and string[0][1] and string[1][0] and string[1][1] and string[2][0] and string[2][1] in alphabet:
     if string[0] is alphabet[0] and string[1] is alphabet[1] and string[2] is alphabet[2] and string[3] is alphabet[3]:
        print(a+b+c+d)   
  </code></pre>
  
  <p>what is the solution? can you help me</p>