345. Inversion of vowel letters in strings

class Solution(object):
    def reverseVowels(self, s):
        """
        :type s: str
        :rtype: str
        """
        sList = list(s)
        p = 0
        q = len(s)-1
        vowels = ['a','e','i','o','u','A','E','I','O','U']
        while p < q:
            while p < len(s) and sList[p] not in vowels:
                p += 1
            while q >= 0 and sList[q] not in vowels :
                q -= 1
            if p >= q:
                break
            tmp = sList[p]
            sList[p] = sList[q]
            sList[q] = tmp
            p += 1
            q -= 1
        return ''.join(sList)