Leetcode58-最后一个单词的长度

思路：

代码：

class Solution:
    def lengthOfLastWord(self, s: str) -> int:
        end = len(s)-1
        while end >= 0 and s[end] == ' ':
            end-=1
        start = end 
        while start >= 0 and s[start] != ' ':
            start-=1
        return end-start