leetcode Longest Palindromic Substring python

class Solution(object):
def longestPalindrome(self, s):
"""
:type s: str
:rtype: str
"""
lenStr = len(s)
if lenStr <= 0:
return 0
maxLen = 0
tmpLen = 0
tmpRes = ''
for i in range(0,lenStr):

#odd numbers
j=0
tmpLen=0
while i-j >= 0 and i+j < lenStr and s[i-j] == s[i+j]:
tmpLen = 2*j +1
j+=1
if tmpLen > maxLen:
maxLen = tmpLen
　　　　　 　　　　#i-j+1 plus one because first: j+=1 then judge s[i-j] == s[i+i]
#so when the while cycle stop, the j is bigger one than the j that make while condition establish
tmpRes = s[i-j+1:i+j]
#even numbers
j=0
tmpLen=0
while i-j>=0 and i+j+1 < lenStr and s[i-j] == s[i+j+1]:
tmpLen = 2*j + 2
j+=1
if tmpLen > maxLen:
maxLen = tmpLen
tmpRes = s[i-j+1:i+j+1]
return tmpRes