211 Add and Search Word - Data Structure Design

class TrieNode(object):
    def __init__(self):
        self.children = dict()
        self.isWord = False

class WordDictionary(object):

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


    def addWord(self, word):
        """
        Adds a word into the data structure.
        :type word: str
        :rtype: None
        """
        node = self.root
        for letter in word:
            child = node.children.get(letter)
            if child is None:
                node.children[letter] = TrieNode()
            node = node.children[letter]
        node.isWord = True

    def search(self, word):
        return self.find(self.root, word)

    def find(self, node, word):
        if word == '':
            return node.isWord
        if word[0] == '.':
            for x in node.children:
                if self.find(node.children[x], word[1:]):
                    return True
        else:
            child = node.children.get(word[0])
            if child:
                return self.find(child, word[1:])
        return False

# Your WordDictionary object will be instantiated and called as such:
# obj = WordDictionary()
# obj.addWord(word)
# param_2 = obj.search(word)