如何使用selenium登录到没有定义ID的网站？

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

# 创建 WebDriver 实例，这里使用 Chrome
driver = webdriver.Chrome()

# 打开网站
driver.get('https://example.com/login')

# 等待登录表单元素加载完成
wait = WebDriverWait(driver, 10)
form_element = wait.until(EC.presence_of_element_located((By.XPATH, '//form')))

# 找到用户名和密码输入框，并填写信息
username_input = form_element.find_element(By.NAME, 'username')
password_input = form_element.find_element(By.NAME, 'password')
username_input.clear()
username_input.send_keys('your_username')
password_input.clear()
password_input.send_keys('your_password')

# 提交登录表单
login_button = form_element.find_element(By.XPATH, '//button[contains(text(), "登录")]')
login_button.click()

# 等待登录成功的元素加载完成，例如欢迎信息
welcome_element = wait.until(EC.presence_of_element_located((By.XPATH, '//div[contains(text(), "欢迎")]')))

# 验证登录成功
print("登录成功")

# 关闭浏览器
driver.quit()