>>> filename=urllib.urlretrieve(url,r"D:\code\sogou.html")

 >>> url2=r'http://www.baidu.com/!@#'

 >>> urllib.quote(url2)

 'http%3A//www.baidu.com/%21%40%23'

 >>> urllib.quote_plus(url2)

 'http%3A%2F%2Fwww.baidu.com%2F%21%40%23'

 >>> urllib.unquote("http%3A//www.baidu.com/%21%40%23")

 'http://www.baidu.com/!@#'

 >>> urllib.unquote_plus("http%3A%2F%2Fwww.baidu.com%2F%21%40%23")

 'http://www.baidu.com/!@#'

 >>>