def XOR(x, y):
 result = ''
 for (a, b) in zip(x, y):
  if (sys.version_info < (3, 0)):
   result += chr((ord(a) ^ ord(b)))
  else:
   result += bytes([(a ^ b)])
 return result

def XOR ( x , y ) : result = '' for ( a , b ) in zip ( x , y ) : if ( sys . version_info < ( 3 , 0 ) ) : result += chr ( ( ord ( a ) ^ ord ( b ) ) ) else : result += bytes ( [ ( a ^ b ) ] ) return result
return the results of an xor operation on two equal length byte strings .