用python自动登录博客园

from selenium import webdriver
import time
a=webdriver.Chrome()
a.get("http:\\www.baidu.com")
a.find_element_by_xpath("//*[@id='kw']").send_keys("博客园")
time.sleep(1)
a.find_element_by_id('su').click()
time.sleep(1)
a.find_element_by_xpath('//*[@id="1"]/h3/a[1]').click()
time.sleep(1)
l=a.window_handles
a.switch_to_window(l[1])
time.sleep(1)
a.find_element_by_xpath('//*[@id="span_userinfo"]/a[1]').click()
time.sleep(1)
a.switch_to_window(l[-1])
time.sleep(1)
a.find_element_by_xpath('//*[@id="LoginName"]').send_keys("用户名")
a.find_element_by_xpath('//*[@id="Password"]').send_keys("密码")
time.sleep(1)
a.find_element_by_xpath('//*[@id="IsRemember"]').click()
time.sleep(1)
a.switch_to_window(l[-1])
time.sleep(1)
a.find_element_by_xpath('//*[@id="submitBtn"]').click()
time.sleep(2)
a.switch_to_window(l[-1])
time.sleep(1)