Length of Last Word

题目：

Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.

If the last word does not exist, return 0.

Note: A word is defined as a character sequence consists of non-space characters only.

For example, 
Given s = "Hello World",
return 5.

解题思路：

直接上代码如下

class Solution:
    # @param {string} s
    # @return {integer}
    def lengthOfLastWord(self, s):
        l = s.split(' ')
        if l==[]:
            return 0
        word = l.pop()
        while word=='':
            if l==[]:
                return 0
            word = l.pop()
        return len(word)