1.安装selenium package:

sudo pip install -U selenium

如果没有pip，先安装pip：

sudo python setup.py install

2.引入selenium package, 建立webdriver对象：

    from selenium import webdriver  
      
      
    sel = selenium.webdriver.Chrome()

在这一步，可能会提示chrome path 的错误，这是因为操作chrome浏览器需要有ChromeDriver的驱动来协助，驱动下载地址：
http://chromedriver.storage.googleapis.com/index.html?path=2.7/ .下载相应版本，并解压到目录

/usr/bin

3.打开设定的url，并等待response:

    loginurl = 'http://weibo.com/'  
    #open the login in page  
    sel.get(loginurl)  
    time.sleep(10)

4.通过xpath找到登录框，并填入相应帐号密码，模拟点击登录：

    #sign in the username  
    try:  
        sel.find_element_by_xpath("//div[@id='pl_login_form']/div/div[2]/div[1]/div[1]/input").send_keys('yourusername')  
        print 'user success!'  
    except:  
        print 'user error!'  
    time.sleep(1)  
    #sign in the pasword  
    try:  
        sel.find_element_by_xpath("//div[@id='pl_login_form']/div/div[2]/div[2]/div[1]/input").send_keys('yourPW')  
        print 'pw success!'  
    except:  
        print 'pw error!'  
    time.sleep(1)  
    #click to login  
    try:  
        sel.find_element_by_xpath("//div[@id='pl_login_form']/div/div[2]/div[6]/a").click()  
        print 'click success!'  
    except:  
        print 'click error!'  
    time.sleep(3)

5.验证登录成功与否，若currenturl发生变化，则认为登录成功：

    curpage_url = sel.current_url  
    print curpage_url  
    while(curpage_url == loginurl):  
        #print 'please input the verify code:'  
        print 'please input the verify code:'  
        verifycode = sys.stdin.readline()  
        sel.find_element_by_xpath("//div[@id='pl_login_form']/div/div[2]/div[3]/div[1]/input").send_keys(verifycode)  
        try:  
            sel.find_element_by_xpath("//div[@id='pl_login_form']/div/div[2]/div[6]/a").click()  
            print 'click success!'  
        except:  
             print 'click error!'  
        time.sleep(3)  
        curpage_url = sel.current_url

6.通过对象的方法获取当前访问网站的session cookie:

    #get the session cookie  
    cookie = [item["name"] + "=" + item["value"] for item in sel.get_cookies()]  
    #print cookie  
      
    cookiestr = ';'.join(item for item in cookie)  
    print cookiestr

7.得到cookie之后，就可以通过urllib2访问相应的网站，并可实现网页爬取等工作：

    import urllib2  
      
      
    print '%%%using the urllib2 !!'  
    homeurl = sel.current_url  
    print 'homeurl: %s' % homeurl  
    headers = {'cookie':cookiestr}  
    req = urllib2.Request(homeurl, headers = headers)  
    try:  
        response = urllib2.urlopen(req)  
        text = response.read()  
        fd = open('homepage', 'w')  
        fd.write(text)  
        fd.close()  
        print '###get home page html success!!'  
    except:  
        print '### get home page html error!!'