Python Trie class - nicer than using just a map and $

trie.py

class TrieNode:
    def __init__(self):
        self.children = {}
        self.ref = 0 # number of references (ie. size of each map)
        self.end = False
    
    def add_word(self, word):
        node = self
        node.ref += 1
        for c in word:
            if c not in node.children:
                node.children[c] = TrieNode()
            node = node.children[c]
            node.ref += 1
        node.end = True
    
    def search(self, word):
        node = self
        for c in word:
        if c not in node.children:
          return False
        node = node.children[c]
        return node.end
    
    def remove_word(self, word):
        node = self
        node.ref -= 1
        for c in word:
            # note: could add early exit here is node.ref == 0
            node = node.children[c]
            node.ref -= 1
        node.end = False # ex. ABC, ABC, ABCD don't want to add ABC twice