code: def equals(val1, val2):
      
      if len(val1) != len(val2):
          return False
      result = 0
      for x, y in zip(val1, val2):
          result |= ord(x) ^ ord(y)
      return result == 0
docs: Returns True if the two strings are equal, False otherwise.
  
      The time taken is independent of the number of characters that match.
  
      For the sake of simplicity, this function executes in constant time only
      when the two strings have the same length. It short-circuits when they
      have different lengths.