Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.
Note: For the purpose of this problem, we define empty string as valid palindrome.
class Solution(object):
def isPalindrome(self, s):
"""
:type s: str
:rtype: bool
"""
s = s.lower()
start_p,end_p = 0,len(s)-1
while(start_p < end_p):
if (s[start_p].isalnum() == False):
start_p+=1
elif (s[end_p].isalnum() == False):
end_p-=1
elif (s[start_p] != s[end_p]) :
return False
else:
start_p+=1
end_p-=1
return True
以上
原文：https://www.cnblogs.com/jyg694234697/p/9528800.html