如何排查定位不到元素：
（1）：元素未加载出来：time.sleep(3)
（2）iframe 问题：driver.switch_to.frame(el)
（3）动态元素
from time import sleep
import time
from selenium import webdriver
from selenium.webdriver import Keys
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.common.by import By
from selenium.webdriver.ie.webdriver import WebDriver
from selenium.webdriver.support.select import Select
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.support.wait import WebDriverWait
#1.创建浏览器对象
driver = webdriver.Chrome(service=Service('/usr/local/bin/chromedriver'))
driver.get("https://mail.163.com/") #打开 163邮箱
driver.maximize_window() #窗口最大
time.sleep(1)
#1.输入用户名
#163邮箱的输入框放在iframe，所以切换到iframe
el = driver.find_element(By.XPATH,".//div[@id='loginDiv']/iframe")
driver.switch_to.frame(el)
el1 = driver.find_element(By.XPATH,".//div[@id='account-box']/div/input[@name='email']")
el1.send_keys("luojie")
#2.输入密码
el2 = driver.find_element(By.NAME,"password")
el2.send_keys("123456")
#3.点击登录
el3 = driver.find_element(By.ID,"dologin")
el3.click()
time.sleep(300)