LeetCode 125. 验证回文串

示例 1:
输入: "A man, a plan, a canal: Panama"
输出: true

示例 2:
输入: "race a car"
输出: false

class Solution:
    def isPalindrome(self, s: str) -> bool:
        pattern='[0-9a-zA-Z]'

        #re.findall正则 lower()转小写 
        s=''.join(re.findall(pattern,s)).lower()
		
		#字符串翻转s[::-1]
        return True if s==s[::-1] else False