Implementation of the Trie data structure

trie.py

class TrieNode:
    def __init__(self, char=None, children={}, terminal=False):
        self.char = char
        self.children = children
        self.terminal = terminal

class Trie:
    def __init__(self):
        self.root = TrieNode()
                             
    def find_prefix(self, prefix):
        trie_node = self.root
                             
        for char in map(str.lower, prefix):
            if char not in trie_node.children:
                return False, trie_node
            
            trie_node = trie_node.children[char]
        
        return True, trie_node
    
    def find_word(self, word):
        found_word_as_prefix, trie_node = self.find_prefix(word)
        
        if found_word_as_prefix:
            return trie_node.terminal == True
               
        return False
    
    def add_word(self, word):
        trie_node = self.root
        
        for char in map(str.lower, word):
            if char not in trie_node.children:
                trie_node.children[char] = TrieNode(char)
            
            trie_node = trie_node.children[char]

        trie_node.terminal = True
  
t = Trie()

t.add_word('hello')
t.add_word('high')

print(t.find_prefix('hell')[0]) # True
print(t.find_prefix('hi')[0]) # True
print(t.find_word('hi')) # False

t.add_word('hi')

print(t.find_word('hi')) # True