class Solution(object):

    def isPalindrome(self, s):
        """
        :type s: str
        :rtype: bool
        """
        rep = ''
        for ss in s.lower():
            if ss in 'qwertyuiopasdfghjklzxcvbnm1234567890':
                rep += ss
        return rep == rep[::-1]

17d066d4fe8915e654caa39b2a0ce32981d07171
<mask token>

class Solution(object):
    <mask token>

class Solution(object):

    def isPalindrome(self, s):
        """
        :type s: str
        :rtype: bool
        """
        rep = ''
        for ss in s.lower():
            if ss in 'qwertyuiopasdfghjklzxcvbnm1234567890':
                rep += ss
        return rep == rep[::-1]
