Python爬虫 —— 知乎之selenium模拟登陆获取cookies+requests.Session()访问+session序列化

即解决了request无法直接script，模拟鼠标操作，又解决了selenium无Session难以维持会话的问题。
以下案例经过改版可以实现代理池和cookies池的应用

coding:utf-8

from selenium import webdriver
import requests
import sys
import time
from lxml import etree
import cPickle
import os

reload(sys)

sys.setdefaultencoding(‘utf-8’)

class Zhihu:
def init(self,homeurl):
self.homeurl = homeurl

def save_session(self,session): #保存session，下次可直接使用，避免再次登录
    with open('session.txt','wb') as f:
        cPickle.dump(session, f)
        print "Cookies have been writed."

def load_session(self):     #加载session
    with open('session.txt', 'rb') as f:
        s = cPickle.load(f)
    return s

def GetCookies(self):       #初次登录用selenium模拟，并获得cookies
    browser = webdriver.Chrome()
    browser.get("https://www.zhihu.com/signin")
    browser.find_element_by_xpath("//main//div[2]/div[1]/form/div[1]/div[2]/div[1]/input").send_keys("13060882373")
    browser.find_element_by_xpath("//main//div[2]/div[1]/form/div[2]/div/div[1]/input").send_keys("xxxxxx")
    browser.find_element_by_xpath("//main//div[2]/div[1]/form/button").click()
    time.sleep(10)
    cookies = browser.get_cookies()
    browser.quit()
    return cookies

def get_session(self):  #获取session
    s = requests.Session()
    if not os.path.exists('session.txt'):   #如果没有session，则创建一个，并且保存到文件中
        s.headers.clear()
        for cookie in self.GetCookies():
            s.cookies.set(cookie['name'], cookie['value'])
        self.save_session(s)
    else:                                   #如果已存在session，则直接加载使用
        s = self.load_session()
    return s

def Crawl(self):    #开始爬取
    s = self.get_session()
    html = s.get(self.homeurl).text
    html_tree = etree.HTML(html)
    items = html_tree.xpath('//main//div[1]/div[2]//div[@class="ContentItem AnswerItem"]/@data-zop')
    for item in items:
        content = eval(item)
        authorName = content['authorName']
        title = content['title']
        print authorName + "回答了：" + title

zhihu = Zhihu(‘https://www.zhihu.com/’)
zhihu.Crawl()