selenium滚动条应用，爬永远讲不完的故事

from selenium import webdriver

class Lj(object):
    def __init__(self):
        self.driver = webdriver.Chrome()
        url = 'http://www.99lib.net/book/1222/34747.htm'
        self.driver.get(url)
        self.driver.maximize_window()
        self.driver.implicitly_wait(10)

    # 获取标题
    def get_title(self):
        dr = self.driver
        title = dr.find_element_by_xpath('//*[@id="content"]/h2').text
        return title

    # 获取内容
    def get_content(self):
        dr = self.driver
        content = dr.find_element_by_xpath('//*[@id="content"]').text
        return content

    # 保存
    def file(self,data):
        with open('永远讲不完的故事.txt','a',encoding='utf-8') as f:
            f.write(data + '\n')

    def gun(self):
        dr = self.driver
        js = "var q=document.documentElement.scrollTop=100000"
        dr.execute_script(js)

    # 翻页
    def next(self):
        dr = self.driver
        dr.find_element_by_link_text('下一页').click()

    # 执行
    def run(self):
        dr = self.driver
        title = self.get_title()
        print(title)
        while True:
            try:
                el = dr.find_element_by_link_text('下一页')
                content = self.get_content()
                self.file(title)
                self.file(content)
                self.next()
                break
            except:
                self.gun()

a = Lj()
while True:
    a.run()