class Solution:
def isPalindrome(self, s: str) -> bool:
# edge case
if len(s) == 0 or len(s) == 1:
return True
i = 0
j = len(s)-1
while i < j:
if self.isAlp(s[i]) == False:
i += 1
elif self.isAlp(s[j]) == False:
j -= 1
else:
if s[i].lower() != s[j].lower():
return False
else:
i += 1
j -= 1
return True
def isAlp(self, ch):
if ch >= 'a' and ch <= 'z':
return True
if ch >= 'A' and ch <= 'Z':
return True
if ch >= '0' and ch <= '9':
return True
return False
string.lower() in Python, convert Capital letter to lower cases.