https://leetcode.com/problems/implement-trie-prefix-tree/description/

implement-trie-prefix-tree.py

class Trie(object):

    def __init__(self):
        """
        Initialize your data structure here.
        """
        self.char_map = {}

    def insert(self, word):
        """
        Inserts a word into the trie.
        :type word: str
        :rtype: void
        """
        if not word: 
            self.char_map[''] = None
            return
        if word[0] not in self.char_map:
            self.char_map[word[0]] = Trie()
        self.char_map[word[0]].insert(word[1:])

    def search(self, word):
        """
        Returns if the word is in the trie.
        :type word: str
        :rtype: bool
        """
        # print 'searching: {}'.format(word)
        if not word: return '' in self.char_map
        if word[0] in self.char_map:
            if self.char_map[word[0]] is None: return False
            return self.char_map[word[0]].search(word[1:])
        return False

    def startsWith(self, prefix):
        """
        Returns if there is any word in the trie that starts with the given prefix.
        :type prefix: str
        :rtype: bool
        """
        # print 'startsWith: {}'.format(prefix)
        if prefix[0] in self.char_map:
            if len(prefix) == 1:
                return True                
            if self.char_map[prefix[0]] is None: return False
            return self.char_map[prefix[0]].startsWith(prefix[1:])
        return False      


# Your Trie object will be instantiated and called as such:
# obj = Trie()
# obj.insert(word)
# param_2 = obj.search(word)
# param_3 = obj.startsWith(prefix)