selenium和casperjs2种数据抓取方式(进来的朋友请留言，共同探讨)

今天用selenium和casperjs2种对https://class.coursera.org/nlp/lecture网站的ppt、pdf、srt、MP4的下载地址进行数据抓取

1、python+selenium

#!/usr/bin/python
# -*- coding: utf-8 -*-

from selenium import webdriver
from bs4 import BeautifulSoup

import time
import sys
reload(sys)
sys.setdefaultencoding('utf-8')

def catchDate(s):
    """页面数据提取"""
    soup = BeautifulSoup(s)
    z = []
    
    m = soup.findAll("ul",class_="course-item-list-section-list")
    
    for obj in m:
        try:
            print obj.previous_sibling.find('h3').get_text()
            tmp = obj.findAll('li', class_="unviewed")
            for eachli in tmp:
                titleli = eachli.find('a').get_text()
                print '          '+titleli
                allaInEachDiv = eachli.find('div', class_="course-lecture-item-resource").findAll('a')
                for eacha in allaInEachDiv:
                    print '      '+eacha['href']
        except Exception, e:
            continue
        if(tmp != ""):
            z.append(tmp)
    return z

starttime = time.time()
driver = webdriver.PhantomJS(executable_path='C:\phantomjs-1.9.7-windows\phantomjs.exe')
driver.get("https://class.coursera.org/nlp/lecture")
html = driver.page_source
content = catchDate(html)
endtime = time.time()
print endtime - starttime
driver.quit

2、casperjs

var casper = require("casper").create({
	clientScripts: ["jquery-1.7.js"],  
    stepTimeout: 120 * 1000,  
    pageSettings: {  
        loadImages: false  
    },  
    verbose: true,  
    logLevel: "error"  
});  
var numberOfLinks = 0;

var fs = require('fs');
var filename = 'content.txt';
var fullContent = "";
var startTime = new Date(), endTime;
  
casper.start("https://class.coursera.org/nlp/lecture", function() {
    numberOfLinks = this.evaluate(function() {
        return __utils__.findAll('.course-item-list-section-list').length;
    });
    this.echo(numberOfLinks + " items found");
});
getStartTime = function(){
	this.echo(startTime);
	this.then(getcontent);
};
getcontent = function() {
    fullContent = this.evaluate(function() {
        var content = "";
        jQuery('.course-item-list-section-list').each(function() {
			var btitle = $(this).prev().find("h3").text();
			content += btitle + '\r\n';
			$(this).find("li").each(function(){
				var stitle = $(this).find("a").first().text();
				content += stitle + '\r';
				$(this).find("div a").each(function(){
					content += $(this).attr("href")+'\r';
				});
				content += '\r\n';
			});
			content += '\r\n\r\n';
        });
        return content;
    });
	this.then(writefile);
};

writefile = function() {
    this.echo('writing to ' + filename);
    fs.write(filename, fullContent, 'w');
	this.then(getEndTime);
};
getEndTime = function(){
	endTime = new Date();
}
casper.then(getStartTime);
casper.then(function exitSystem() {
	this.echo(new Date() - startTime);
    casper.exit();  
}); 

casper.run();

因为不熟练，感觉写的不太好，求大神对方法进行指导！！！

参考：

https://gist.github.com/imjared/5201405

http://casperjs.readthedocs.org/en/latest/modules/casper.html#evaluate

http://blog.csdn.net/u012577500/article/details/18185399

http://stackoverflow.com/questions/14894311/casperjs-windows-installation-how-is-it-done-the-correct-way-please

http://blog.csdn.net/sagomilk/article/details/20800543