import urllib
def downURL(url,filename):
  try:
    fp=urllib.urlopen(url)
  except:
    print('download error')
    return 0
  op=open(filename,'wb')
  while 1:
     s=fp.read()
     if not s:
       break
     op.write(s)
  fp.close()
  op.close()
  return 1
downURL("http://www.baidu.com","C:\\url.txt")