gistfile1.py

import urllib2

class BigFileDownloader(object):
 
  def __init__(self, url, file):
    self.packet_size = 128
    self.urlopener = urllib2.build_opener()
    self.url = url
    self.file = file

  def download(self):
    try:
      request = urllib2.Request(self.url)
      fout = open(self.file, "wb")
      datafd = self.urlopener.open(request)
      totalsize = int(datafd.headers.get("content-length"))*8
      while True:
        data = datafd.read(self.packet_size)
        if not data:
          break
        fout.write(data)
      fout.close()
    except Exception, e: 
      logging.critical("Cannot download %s"%str(e))