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
driver=webdriver.Firefox()#启动浏览器
driver.get('http://localhost/upload/user.php')#打开前台登录页
driver.find_element(By.NAME,'submit').click()#立即登录
# 显式等待：等待条件是消息框出现
WebDriverWait(driver,10).until(EC.alert_is_present())
# 切换到消息框
a1=driver.switch_to.alert
# 点击“确定”
a1.accept()
driver.quit()