1.定位登陆框iframe
2.定位到邮箱地址框name
3.定位到密码地址name
4.定位到登陆按钮id
虫师在《Selenium2 自动化测试实战》上给的登陆代码用不了，原因是因为网站为了防止被爬虫，将登陆id和iframe的id都是随机的，导致定位元素失败。
#coding:utf-8
from selenium import webdriver
import time
import re
dr = webdriver.Firefox()
dr.get("https://www.126.com")
dr.maximize_window()
time.sleep(5)
dr.switch_to.frame(dr.find_element_by_tag_name("iframe"))
#dr.switch_to.frame(0)
email = dr.find_element_by_name("email")
email.send_keys("sfgdfgdfg")
password = dr.find_element_by_name("password")
password.send_keys("dsvdfvsd")
login_bth = dr.find_element_by_id("dologin")
login_bth.click()
time.sleep(10)