抓取网易公开课并下载

原文地址：http://bbs.csdn.net/topics/390361293

# -*- coding: utf-8 -*-
#抓取网易公开课下载链接
#By  : hnicypb@126.com
#Ver :1.0
#Time:2013-12-30
#Python 2.7 + BeautifulSoup 3.03(用最新版本4.1乱码没搞定，退回3.03)
#eg: python 抓取网易公开课.py http://v.163.com/special/opencourse/paradigms.html

from BeautifulSoup import BeautifulSoup
import re
import sys,os
import urllib

#显示百分比
def rpb(blocknum, blocksize, totalsize):
    percent = 100.0 * blocknum * blocksize / totalsize
    if percent > 100:percent = 100
    print "%.2f%%"% percent
    
def downlaod(url):
    #获取页面
    html = urllib.urlopen(url).read()
    #用美汤来装载
    soup = BeautifulSoup(html)
    #获取课程信息，名称，简介等
    title = soup.find('div',{"class" : "m-cdes"})
    print title.h2.string
    print title.findAll('p')[0].string
    print title.findAll('p')[1].string
    print title.findAll('p')[2].string

    #获取课程详细列表信息
    detail=soup.findAll('tr',{"class" : "u-even"})
    for i in detail:
        #获取课程名称
        name=i.find('td',{"class" : "u-ctitle"}) 
        fileName=name.contents[0].strip() .lstrip() .rstrip(',') + name.a.string.strip() .lstrip() .rstrip(',')
        #获取课程下载链接
        downInfo=i.find('td',{"class" : "u-cdown"})
        downLink=downInfo.a['href']
        
        print fileName
        print downLink
        
        #使用urlretrieve下载该文件
        if not os.path.exists(fileName):
            urllib.urlretrieve(downLink,fileName+".mp4",rpb)
    
def main(argv):
    if len(argv)>=2:
         downlaod(argv[1])

if __name__=="__main__":
     main(sys.argv)