在Python中使用CasperJS获取JS渲染生成的HTML内容的教程

文章摘要：其实这里casperjs与python没有直接关系,主要依赖casperjs调用phantomjs webkit获取html文件内容。长期以来，爬虫抓取 客户端javascript渲染生成的html页面 都极为 困难, Java里面有 HtmlUnit, 而Python里，我们可以使用独立的跨平台的CasperJS。

    创建site.js(接口文件，输入:url，输出:html file)  

   //USAGE: E:\toolkit\n1k0-casperjs-e3a77d0\bin>python casperjs site.js --url=http://spys.ru/free-proxy-list/IE/ --outputfile='temp.html' 

    var fs = require('fs');
    var casper = require('casper').create({
     pageSettings: {
     loadImages: false,
     loadPlugins: false,
     userAgent: 'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/34.0.1847.137 Safari/537.36 LBBROWSER'
    },
    logLevel: "debug",//日志等级
    verbose: true  // 记录日志到控制台
     });
    var url = casper.cli.raw.get('url');
    var outputfile = casper.cli.raw.get('outputfile');
    //请求页面
    casper.start(url, function () {
    fs.write(outputfile, this.getHTML(), 'w');
    }); 

    casper.run();

    python 代码, checkout_proxy.py      

 import json
    import sys
    #import requests
    #import requests.utils, pickle
    from bs4 import BeautifulSoup
    import os.path,os
    import threading
    #from multiprocessing import Process, Manager
    from datetime import datetime
    import traceback
    import logging
    import re,random
    import subprocess
    import shutil
    import platform 

    output_file = os.path.join(os.path.dirname(os.path.realpath(__file__)),'proxy.txt')
    global_log = 'http_proxy' + datetime.now().strftime('%Y-%m-%d') + '.log'
    if not os.path.exists(os.path.join(os.path.dirname(os.path.realpath(__file__)),'logs')):
      os.mkdir(os.path.join(os.path.dirname(os.path.realpath(__file__)),'logs'))
    global_log = os.path.join(os.path.dirname(os.path.realpath(__file__)),'logs',global_log) 

    logging.basicConfig(level=logging.DEBUG,format='[%(asctime)s] [%(levelname)s] [%(module)s] [%(funcName)s] [%(lineno)d] %(message)s',filename=global_log,filemode='a')
    log = logging.getLogger(__name__)
    #manager = Manager()
    #PROXY_LIST = manager.list()
    mutex = threading.Lock()
    PROXY_LIST = [] 

    def isWindows():
      if "Windows" in str(platform.uname()):
      return True
      else:
      return False 

    def getTagsByAttrs(tagName,pageContent,attrName,attrRegValue):
      soup = BeautifulSoup(pageContent)
      return soup.find_all(tagName, { attrName : re.compile(attrRegValue) }) 

    def getTagsByAttrsExt(tagName,filename,attrName,attrRegValue):
      if os.path.isfile(filename):
      f = open(filename,'r')
      soup = BeautifulSoup(f)
      f.close()
      return soup.find_all(tagName, { attrName : re.compile(attrRegValue) })
      else:
      return None 

    class Site1Thread(threading.Thread):
      def __init__(self,outputFilePath):
        threading.Thread.__init__(self)
      self.outputFilePath = outputFilePath
      self.fileName = str(random.randint(100,1000)) + ".html"
      self.setName('Site1Thread') 

      def run(self):
      site1_file = os.path.join(os.path.dirname(os.path.realpath(__file__)),'site.js')
      site2_file = os.path.join(self.outputFilePath,'site.js')
      if not os.path.isfile(site2_file) and os.path.isfile(site1_file):
        shutil.copy(site1_file,site2_file)
      #proc = subprocess.Popen(["bash","-c", "cd %s && ./casperjs site.js --url=http://spys.ru/free-proxy-list/IE/ --outputfile=%s" % (self.outputFilePath,self.fileName) ],stdout=subprocess.PIPE)
      if isWindows():
        proc = subprocess.Popen(["cmd","/c", "%s/casperjs site.js --url=http://spys.ru/free-proxy-list/IE/ --outputfile=%s" % (self.outputFilePath,self.fileName) ],stdout=subprocess.PIPE)
      else:
        proc = subprocess.Popen(["bash","-c", "cd %s && ./casperjs site.js --url=http://spys.ru/free-proxy-list/IE/ --outputfile=%s" % (self.outputFilePath,self.fileName) ],stdout=subprocess.PIPE)
      out=proc.communicate()[0]
      htmlFileName = ''
      #因为输出路径在windows不确定，所以这里加了所有可能的路径判断
      if os.path.isfile(self.fileName):
        htmlFileName = self.fileName
      elif os.path.isfile(os.path.join(self.outputFilePath,self.fileName)):
        htmlFileName = os.path.join(self.outputFilePath,self.fileName)
      elif os.path.isfile(os.path.join(os.path.dirname(os.path.realpath(__file__)),self.fileName)):
        htmlFileName = os.path.join(os.path.dirname(os.path.realpath(__file__)),self.fileName)
      if (not os.path.isfile(htmlFileName)):
        print 'Failed to get html content from http://spys.ru/free-proxy-list/IE/'
        print out
        sys.exit(3)
      mutex.acquire()
      PROXYList= getTagsByAttrsExt('font',htmlFileName,'class','spy14$')
      for proxy in PROXYList:
        tdContent = proxy.renderContents()
        lineElems = re.split('[<>]',tdContent)
        if re.compile(r'\d+').search(lineElems[-1]) and re.compile('(\d+\.\d+\.\d+)').search(lineElems[0]):
        print lineElems[0],lineElems[-1]
        PROXY_LIST.append("%s:%s" % (lineElems[0],lineElems[-1]))
      mutex.release()
      try:
        if os.path.isfile(htmlFileName):
        os.remove(htmlFileName)
      except:
        pass 

    if __name__ == '__main__':
      try:
      if(len(sys.argv)) < 2:
        print "Usage:%s [casperjs path]" % (sys.argv[0])
        sys.exit(1)
      if not os.path.exists(sys.argv[1]):
        print "casperjs path: %s does not exist!" % (sys.argv[1])
        sys.exit(2)
      if os.path.isfile(output_file):
        f = open(output_file)
        lines = f.readlines()
        f.close
        for line in lines:
        PROXY_LIST.append(line.strip())
      thread1 = Site1Thread(sys.argv[1])
      thread1.start()
      thread1.join() 

      f = open(output_file,'w')
      for proxy in set(PROXY_LIST):
        f.write(proxy+"\n")
      f.close()
      print "Done!"
      except SystemExit:
      pass
      except:
        errMsg = traceback.format_exc()
        print errMsg
        log.error(errMsg)