以下是从163源下载openstack-ocata版软件包的脚本：

from html.parser import HTMLParserfrom urllib import requestimport urllibimport os,sysimport socketclass myparser(HTMLParser):    '''找到a标签并把属性的值放到列表里'''    def __init__(self):        HTMLParser.__init__(self)        self.links = []    def handle_starttag(self, tag, attrs):        if tag == 'a':            if len(attrs) == 0:                pass            else:                for (variable,value) in attrs:#                    print(value)                    if variable == 'href':                        self.links.append(value)def callbackfunc(blocknum, blocksize, totalsize):    '''回调函数,打印下载进度    @blocknum: 已经下载的数据块    @blocksize: 数据块的大小    @totalsize: 远程文件的大小    '''    percent = int(100.0 * blocknum * blocksize / totalsize)    if totalsize > 505528:        pass    else:        percent = 100    sys.stdout.write('\r')    sys.stdout.write(file_name + percent * '>' + str(percent) + '%')    sys.stdout.flush()def create_dir(root_tree,catalog):    '''根据url的目录结构在本地穿件文件夹'''    os.chdir(root_tree)    try:        os.makedirs(catalog)    except FileExistsError as e:        passdef download_file(url,down_path):    '''下载文件保存到相应的目录，并把下载失败的放在一个字典里'''    global file_name    global error_download    file_name =  url.split('/')[-1]    error_download = {}    socket.setdefaulttimeout(30)    try:        request.urlretrieve(url,down_path,callbackfunc)    except socket.gaierror as e:        error_download[url] = down_path        print('socket.gaierror' , url)    except urllib.error.URLError as e:        error_download[url] = down_path        print('urllib.error.URLError',url)    sys.stdout.write('\n')def get_url_tree(url_tree):    '''获取一个字典，链接：目录，并把文件夹创建及把文件下载'''    url_tree_dict = {}    level = 0    for url in url_tree:        response = request.urlopen(url)        page = response.read().decode('utf-8')        hp = myparser()        hp.feed(page)        hp.close()        try:            hp.links.remove("../")        except ValueError as e:            pass        for file in hp.links:            if '/' in file:                create_dir(url_tree[url], file)                url_tree_dict[url+file] = url_tree[url]+file            else:                download_file(url+file,url_tree[url]+file)            if file.find('/') > 0:                level += 1    return url_tree_dict , levelurl_tree = {
   "http://mirrors.163.com/centos/7/cloud/x86_64/openstack-ocata/":'/centos/7/cloud/x86_64/openstack-ocata/'}try:    os.makedirs('/centos/7/cloud/x86_64/openstack-ocata/')except FileExistsError as e:    passwhile True:    url_tree,level = get_url_tree(url_tree)    if level == 0:        break    print(url_tree,level)for key in error_download:    download_file(key,error_download[key])