如何从XML向表中插入空值？

import xml.etree.ElementTree as ET
import mysql.connector

# 解析XML
tree = ET.parse('data.xml')
root = tree.getroot()

# 连接到MySQL数据库
cnx = mysql.connector.connect(user='username', password='password', host='localhost', database='database')
cursor = cnx.cursor()

# 遍历XML中的数据
for item in root.findall('item'):
    # 提取需要插入的数据
    name = item.find('name').text
    age = item.find('age').text
    address = item.find('address').text

    # 构造插入语句
    if name is None:
        name = 'NULL'
    if age is None:
        age = 'NULL'
    if address is None:
        address = 'NULL'

    insert_query = "INSERT INTO table_name (name, age, address) VALUES ({}, {}, {})".format(name, age, address)

    # 执行插入语句
    cursor.execute(insert_query)

# 提交更改并关闭连接
cnx.commit()
cursor.close()
cnx.close()