[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
1 #coding=utf-8
2 import urllib2,re
3
4 def getHtml(url):
5 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'}
6 request = urllib2.Request(url,headers=header) #init user request with url and headers
7 response = urllib2.urlopen(request) #open url
8 text = response.read()
9 return text
10
11 def getTitleLink(html):
12 pattern1 = re.compile('<a class="title" target="_blank" href="/p/(\w{0,12})"', re.S)
13 links = re.findall(pattern1,html)
14 urls = ["www.jianshu.com/p/"+str(link) for link in links]
15
16 pattern2 = re.compile('<a class="title" target="_blank" href="/p/.*?">(.*?)</a>',re.S)
17 titles = re.findall(pattern2,html)
18 for title,url in zip(titles,urls):
19 if r'目录' not in title:
20 print "["+title+"](" + url + ")"
21 #return urls
22
23
24 #sample test menu
25 url = 'http://www.jianshu.com/u/73632348f37a'
26 html = getHtml(url)
27 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
1 #coding=utf-8
2
3 #refer to http://www.cnblogs.com/haigege/p/5492177.html
4 #Step1: scroll and generate Markdown format Menu
5
6 from selenium import webdriver
7 import time
8
9 def scroll_top(driver):
10 if driver.name == "chrome":
11 js = "var q=document.body.scrollTop=0"
12 else:
13 js = "var q=document.documentElement.scrollTop=0"
14 return driver.execute_script(js)
15
16 # 拉到底部
17 def scroll_foot(driver):
18 if driver.name == "chrome":
19 js = "var q=document.body.scrollTop=100000"
20 else:
21 js = "var q=document.documentElement.scrollTop=100000"
22 return driver.execute_script(js)
23
24 def write_text(filename, info):
25 """
26 :param info: 要写入txt的文本内容
27 :return: none
28 """
29 # 创建/打开info.txt文件，并写入内容
30 with open(filename, 'a+') as fp:
31 fp.write(info.encode('utf-8'))
32 fp.write('\n'.encode('utf-8'))
33 fp.write('\n'.encode('utf-8'))
34
35 def sroll_multi(driver,times=5,loopsleep=2):
36 #40 titles about 3 times
37 for i in range(times):
38 time.sleep(loopsleep)
39 print "Scroll foot %s time..." % i
40 scroll_foot(driver)
41 time.sleep(loopsleep)
42
43 #Note: titles is titles_WebElement type object
44 def write_menu(filename,titles):
45 with open(filename, 'w') as fp:
46 pass
47 for title in titles:
48 if r'目录' not in title.text:
49 print "[" + title.text + "](" + title.get_attribute("href") + ")"
50 t = title.text.encode('utf-8')
51 t = title.text.replace(":", "：")
52 t = title.text.replace("|", "丨")
53 t = title.text.decode('utf-8')
54 write_text(filename, "[" + t + "](" + title.get_attribute("href") + ")")
55 #assert type(title) == "WebElement"
56 #print type(title)
57
58 def main(url):
59 # eg. <a class="title" href="/p/6f543f43aaec" target="_blank"> titleXXX</a>
60 driver = webdriver.Firefox()
61 driver.implicitly_wait(10)
62 # driver.maximize_window()
63 driver.get(url)
64 sroll_multi(driver)
65 titles = driver.find_elements_by_xpath('.//a[@class="title"]|.//a[target="_blank"]')
66 write_menu(filename, titles)
67
68 if __name__ == '__main__':
69 # sample link
70 url = 'http://www.jianshu.com/u/73632348f37a'
71 filename = r'info.txt'
72 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')