def findTheDifference(self, s, t):
        """
        :type s: str
        :type t: str
        :rtype: str
        """
        res = ord(t[-1])
        for i in range(len(s)):
            res += ord(t[i])
            res -= ord(s[i])
        return chr(res)

        :type s: str
        :type t: str
        :rtype: str
        
python/389_Find_the_Difference.py