mycode   12.51%

class Solution(object):
def longestPalindrome(self, s):
"""
:type s: str
:rtype: str
"""
length = len(s)
if length==0:
return ''
res = s[0]
for i in range(length-1):
for j in range(i+1,length):
if s[j] == s[i]:
temp = s[i:j+1]
if temp == temp[::-1]:
if len(temp) > len(res):
res = temp[:]
return res

参考：

class Solution(object):
def longestPalindrome(self, s):
"""
:type s: str
:rtype: str
"""
n = len(s)
maxl, start = 0, 0
for i in range(n):
if i - maxl >= 1 and s[i-maxl-1:i+1] == s[i-maxl-1:i+1][::-1]:
start = i - maxl - 1
maxl += 2
continue
if i - maxl >= 0 and s[i-maxl:i+1] == s[i-maxl:i+1][::-1]:
start = i - maxl
maxl += 1
return s[start: start + maxl]