Python实现的下载8000首儿歌的代码分享

from pyquery import PyQuery as py
from lxml import etree
import urllib
import re
import os
import sys
import logging

def format(filename):
    tuple=(' ',''','/'')
    for char in tuple:
        if (filename.find(char)!=-1):
            filename=filename.replace(char,"_")
    return filename

def download_mp3(mp3_url, filename,dir):      
    f = dir+"//"+filename
    if os.path.exists(f):
      logger.debug(f+" is existed.")
      return
     
    try:
        open(f, 'wb').write(urllib.urlopen(mp3_url).read())
        logger.debug(  filename + ' is downloaded.')
    except:
        logger.debug( filename + ' is not downloaded.')

       
def download_all_mp3(start,end,dir,logger):
  for x in range(start,end):
    try:
        url = "http://www.youban.com/mp3-d" + str(x) + ".html"
        logger.debug(str(x) + ": "+url)
        doc = py(url=url)
        e = doc('.mp3downloadbox')
        if e is None or e == '':
          logger.debug(url+" is not existed.")
          return
         
        e = unicode(e)
        #logger.debug( e)
        regex = re.compile(ur".*<h1>(.*)</h1>.*downloadboxlist.*?<a.*?/"(.*?)/"",re.UNICODE|re.S)
        m = regex.search(e)
        if m is not None:
          title = m.group(1).strip()
          title2 = str(x)+"_"+title + ".mp3"
          #title2 = re.sub(' ','_',title2)
          title2 = format(title2)
          link = m.group(2)
          #logger.debug( "title:" + title + " link:" + link)
          if link == '' or title == '':
            logger.debug(url + " is not useful")
            continue
          logger.debug(str(x)+": "+link)
          download_mp3(link,title2,dir)
    except:
        logger.debug(url+" met exception.")
        continue
     

     
if __name__ == "__main__":
    dir_root = "e://song"
    if sys.argv[3] != '': dir_root=sys.argv[3]
   
    start,end = 1,8000
    if sys.argv[1] >= 0 and sys.argv[2]>=0:
      start,end = int(sys.argv[1]),int(sys.argv[2])
      print ("Download from %s to %s./n" % (start,end))     
   
    dir = dir_root + "//"+str(start)+"-"+str(end)
    if not os.path.exists(dir):
      os.mkdir(dir)    
    print "Download to " + dir + "./n"
   
    logger = logging.getLogger("simple")
    logger.setLevel(logging.DEBUG) 
    fh = logging.FileHandler(dir+"//"+"download.log")
    ch = logging.StreamHandler()
    formatter = logging.Formatter("%(message)s")
    ch.setFormatter(formatter)
    fh.setFormatter(formatter)
    logger.addHandler(ch)
    logger.addHandler(fh)
    download_all_mp3(start,end,dir,logger)