code: def hamming_distance(s1, s2, equality_function=operator.eq):
      
      if not len(s1) == len(s2):
          raise ValueError("String lengths are not equal")
  
      # Number of non-matching characters:
      return sum(not equality_function(c1, c2) for c1, c2 in zip(s1, s2))
docs: Returns the hamming distance between two strings.