Leetcode 3. Longest Substring Without Repeating Characters（python）

class Solution(object):
def lengthOfLongestSubstring(self, s):
"""
:type s: str
:rtype: int
"""
if len(s)<=1:
return len(s)
point=0
maxl=0
for index in range(1,len(s)):
if s[index] in s[point:index]:
l=index-point
if l>=maxl:
maxl=l
point+=s[point:index].index(s[index])+1
if index-point+1>maxl:
maxl=index-point+1

return maxl