input: 
  def digitSum(s):
      """Task
      Write a function that takes a string as input and returns the sum of the upper characters only'
      ASCII codes.
  
      Examples:
          digitSum("") => 0
          digitSum("abAB") => 131
          digitSum("abcCd") => 67
          digitSum("helloE") => 69
          digitSum("woArBld") => 131
          digitSum("aAaaaXa") => 153
      """
  
output:     total = 0
      for char in s:
          if char.isupper():
              total += ord(char)
      return total