Longest Word in Dictionary

Longest Word in Dictionary.py

class Solution(object):
    def longestWord(self, words):
        """
        :type words: List[str]
        :rtype: str
        """
        wSet =set([''])
        ans = ''
        
        for word in sorted(words):
            if word[:-1] in wSet:
                wSet.add(word)
                if len(word) > len(ans):
                    ans = word
                
        return ans