208.py

'''
	Implement a trie with insert, search, and startsWith methods.
'''
class TreeNode(object):
	self.word = False
	self.children = {}

class Trie(object):

    def __init__(self):
        """
        Initialize your data structure here.
        """
        self.root = TreeNode()

    def insert(self, word):
        """
        Inserts a word into the trie.
        :type word: str
        :rtype: void
        """
        node = self.root
        for char in word:
        	if char not in node.children:
        		node.children[char] = TreeNode()
        	node = node.children[char]
        node.word = True

    def search(self, word):
        """
        Returns if the word is in the trie.
        :type word: str
        :rtype: bool
        """
        node = self.root
        for char in word:
        	if char not in node.children:
        		return False
        	node = node.children[char]
        return node.word 
        

    def startsWith(self, prefix):
        """
        Returns if there is any word in the trie that starts with the given prefix.
        :type prefix: str
        :rtype: bool
        """
        node = self.root
        for char in prefix:
        	if char not in node.children:
        		return False
        	node = node.children[char]
        return True
        


# 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)