code: def string_xor(a, b):
      '''Computes the XOR operator between two byte strings. If the strings are
         of different lengths, the result string is as long as the shorter.
      '''
      if sys.version_info[0] < 3:
          return ''.join((chr(ord(x) ^ ord(y)) for (x, y) in zip(a, b)))
      else:
          return bytes(x ^ y for (x, y) in zip(a, b)f string_xor(a, b):
      '''Computes the XOR operator between two byte strings. If the strings are
         of different lengths, the result string is as long as the shorter.
      '''
      if sys.version_info[0] < 3:
          return ''.join((chr(ord(x) ^ ord(y)) for (x, y) in zip(a, b)))
      else:
          return bytes(x ^ y for (x, y) in zip(a, b))
docs: Computes the XOR operator between two byte strings. If the strings are
         of different lengths, the result string is as long as the shorter.