Python 字典树的持久化与数据库存储

import pickle
import sqlite3

class TrieNode:
    def __init__(self, char: str):
        self.char = char
        self.children = {}
        self.is_end_of_word = False

def insert(root: TrieNode, word: str):
    node = root
    for char in word:
        if char not in node.children:
            node.children[char] = TrieNode(char)
        node = node.children[char]
    node.is_end_of_word = True

def build_trie(words: list):
    root = TrieNode('')
    for word in words:
        insert(root, word)
    return root

def persist_trie(root: TrieNode):
    with sqlite3.connect('trie.db') as conn:
        cursor = conn.cursor()
        cursor.execute('CREATE TABLE IF NOT EXISTS trie (node BLOB, char TEXT NOT NULL, is_end_of_word INTEGER NOT NULL)')
        queue = [(root, None)]
        while queue:
            node, parent = queue.pop(0)
            cursor.execute('INSERT INTO trie (node, char, is_end_of_word) VALUES (?, ?, ?)', (
                pickle.dumps(parent),
                node.char,
                1 if node.is_end_of_word else 0
            ))
            for child in node.children.values():
                queue.append((child, node))

def load_trie():
    with sqlite3.connect('trie.db') as conn:
        cursor = conn.cursor()
        cursor.execute('SELECT node, char, is_end_of_word FROM trie')
        rows = cursor.fetchall()
        nodes = {}
        for node, char, is_end_of_word in rows:
            node = pickle.loads(node)
            if node is None:
                root = TrieNode(char)
                nodes[root] = root
            else:
                child = TrieNode(char)
                setattr(node, char, child)
                nodes[child] = child
            if is_end_of_word:
                nodes[child].is_end_of_word = True
    return root

# 示例
words = ['pidancode.com', 'python', 'code', 'coding']
root = build_trie(words)
persist_trie(root)
root = load_trie()

# 进行查询等操作