如何停止运行在python中的selenium脚本，然后从头开始重新启动？

from selenium import webdriver
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.action_chains import ActionChains
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

driver = webdriver.Chrome()  # 创建一个Chrome浏览器的WebDriver对象

# 执行一些操作，例如打开网页、填写表单等
driver.get("https://www.example.com")
element = driver.find_element_by_id("username")
element.send_keys("username")
element = driver.find_element_by_id("password")
element.send_keys("password")
element.send_keys(Keys.RETURN)

driver.quit()  # 关闭浏览器并停止WebDriver对象的执行

driver = webdriver.Chrome()  # 创建一个新的Chrome浏览器的WebDriver对象