Find Smallest Letter Greater Than Target

Find Smallest Letter Greater Than Target.py

class Solution(object):
    def nextGreatestLetter(self, letters, target):
        """
        :type letters: List[str]
        :type target: str
        :rtype: str
        """
        letters = set(map(ord, letters))
        for x in range(1, 27):
            candidate = ord(target) + x
            if candidate > ord('z'):
                candidate -= 26
            if candidate in letters:
                return chr(candidate)