[Selenium2+python2.7][Scrap]爬虫和selenium方式下拉滚动条获取简书作者目录并且生成Markdown格式目录

预计阅读时间： 15分钟

环境： win7 + Selenium2.53.6+python2.7 +Firefox 45.2  (具体配置参考 http://www.cnblogs.com/yoyoketang/p/selenium.html)

FF45.2 官方下载地址： http://ftp.mozilla.org/pub/firefox/releases/45.2.0esr/win64/en-US/

痛点：爸爸的一个朋友最近简书上面更新了20多篇文章，让我添加目录。每次手动查找链接再添加标题太麻烦了，30多篇就需要半个多小时，而且链接可能会变换。

解决办法：由于简书支持markdown 格式，爬取作者目录然后生成Markdown格式文档即可

原始思路一： 采用urllib2方式爬取目录

步骤：

1.使用urllib2模拟header  request打开页面

2. 采用正则匹配href的链接，然后用列表推导式生成链接

3. 采用正则获取标题

4. 生成目录

 #coding=utf-8
 import urllib2,re

 def getHtml(url):
     header = {"User-Agent":'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.101 Safari/537.36'}
     request = urllib2.Request(url,headers=header)  #init user request with url and headers
     response = urllib2.urlopen(request)            #open url
     text = response.read()
     return text

 def getTitleLink(html):
     pattern1 = re.compile('<a class="title" target="_blank" href="/p/(\w{0,12})"', re.S)
     links = re.findall(pattern1,html)
     urls = ["www.jianshu.com/p/"+str(link) for link in links]

     pattern2 = re.compile('<a class="title" target="_blank" href="/p/.*?">(.*?)</a>',re.S)
     titles = re.findall(pattern2,html)
     for title,url in zip(titles,urls):
         if r'目录' not in title:
             print "["+title+"](" + url + ")"
     #return urls

 #sample test menu
 url = 'http://www.jianshu.com/u/73632348f37a'
 html = getHtml(url)
 getTitleLink(html)

测试发现如果作者文章只有五六篇，能正确生成。

但是如果文章20篇以上，发现问题：

这种办法只爬取了当前页面加载的文章链接，手工拖拽滚动条动态加载的标题内容无法直接获取到，网上建议用selenium来解决

思路二： 采用selenium打开网页，调用js模拟鼠标点击滚动条，加载全部页面

步骤：

1. 使用selenium打开网页

2. 循环调用js模拟鼠标点击下拉滚动条，直至加载全部页面

3. 使用find_elements_by_xpath查找标题tag

4. 将标题tag解析后写入目录并打印

注： 步骤3获取的为WebElement 类型对象

 #coding=utf-8

 #refer to http://www.cnblogs.com/haigege/p/5492177.html
 #Step1: scroll and generate Markdown format Menu

 from selenium import webdriver
 import time

 def scroll_top(driver):
     if driver.name == "chrome":
         js = "var q=document.body.scrollTop=0"
     else:
         js = "var q=document.documentElement.scrollTop=0"
     return driver.execute_script(js)

 # 拉到底部
 def scroll_foot(driver):
     if driver.name == "chrome":
         js = "var q=document.body.scrollTop=100000"
     else:
         js = "var q=document.documentElement.scrollTop=100000"
     return driver.execute_script(js)

 def write_text(filename, info):
     """
     :param info: 要写入txt的文本内容
     :return: none
     """
     # 创建/打开info.txt文件，并写入内容
     with open(filename, 'a+') as fp:
         fp.write(info.encode('utf-8'))
         fp.write('\n'.encode('utf-8'))
         fp.write('\n'.encode('utf-8'))

 def sroll_multi(driver,times=5,loopsleep=2):
     #40 titles about 3 times
     for i in range(times):
         time.sleep(loopsleep)
         print "Scroll foot %s time..." % i
         scroll_foot(driver)
     time.sleep(loopsleep)

 #Note: titles is titles_WebElement type object
 def write_menu(filename,titles):
     with open(filename, 'w') as fp:
         pass
     for title in titles:
         if r'目录' not in title.text:
             print "[" + title.text + "](" + title.get_attribute("href") + ")"
             t = title.text.encode('utf-8')
             t = title.text.replace(":", "：")
             t = title.text.replace("|", "丨")
             t = title.text.decode('utf-8')
             write_text(filename, "[" + t + "](" + title.get_attribute("href") + ")")
             #assert type(title) == "WebElement"
             #print type(title)

 def main(url):
     # eg. <a class="title" href="/p/6f543f43aaec" target="_blank"> titleXXX</a>
     driver = webdriver.Firefox()
     driver.implicitly_wait(10)
     # driver.maximize_window()
     driver.get(url)
     sroll_multi(driver)
     titles = driver.find_elements_by_xpath('.//a[@class="title"]|.//a[target="_blank"]')
     write_menu(filename, titles)

 if __name__ == '__main__':
     # sample link
     url = 'http://www.jianshu.com/u/73632348f37a'
     filename = r'info.txt'
     main(url)

注：

1. 参考链接： http://www.cnblogs.com/haigege/p/5492177.html

2. 环境下载:Firefox45: https://ftp.mozilla.org/pub/firefox/releases/45.0esr/win64/en-US/

3. 如果编码格式报错，添加

reload(sys)
sys.setdefaultencoding('utf8')