Python implementation of Youku video batch download function

import urllib,urllib2,sys,os
from BeautifulSoup import BeautifulSoup
import itertools,re
url_i =1
pic_num = 1
# Self-defined quote format conversion function
def _en_to_cn(str):
  obj = (['“','”'])
  _obj = lambda x: ()
  return (r"['\"]",_obj,str)
if __name__ == '__main__':
  #Download videos from 3 consecutive web pages
  while url_i <= 3:
    webContent = ("/focus/index/_page26716_" + str(url_i) + ".html")
    data = ()
    #Read video listings web page data with BeautifulSoup
    soup = BeautifulSoup(data)
    print "-------------------------Page " + str(url_i) + "-------------------------"
    # Get a list of the video thumbnail and title of the corresponding page
    tag_list_thumb = ('li','v_thumb')
    tag_list = ('li', "v_title")
    for item in tag_list:
      #Directs to the video playback page via herf in each thumbnail
      web_video_play = (['href'])
      data_vp = web_video_play.read()
      # Read video playback web page data with BeautifulSoup
      soup_vp = BeautifulSoup(data_vp)
      # Find the link for "Download".
      tag_vp_list = soup_vp.findAll('a', id = 'fn_download')
      for item_vp in tag_vp_list:
        #Save the download link to url_dw
        url_dw = '"' + item_vp['_href'] + '"'
        print ['title'] + ": " + url_dw
        # Invoke the command line to run iku to download the video, you need to add iku to the environment variable
        ("iku " + url_dw)
    #Savethumbnail for each video
    for item_thumb in tag_list_thumb:
      (item_thumb.img['src'], "E:\\\\ Download video\\\\thumbnails\\\" + str(pic_num) + "." +
                _en_to_cn(item_thumb.img['title']) + ".jpg")
      pic_num += 1
    print "--------------------------------------------------------------"
    print "--------Page " + str(url_i) + "'s video thumbnails have been saved!"
    url_i += 1