python解压TAR文件至至指定文件夹

#########  Extract all files from src_dir to des_dir
def extract_tar_files(src_dir,des_dir):
    files = os.listdir(src_dir)
    for file in files:
        dir_tmp = os.path.join(src_dir, file)
        print dir_tmp
        if not os.path.isdir(dir_tmp): ##是文件，非文件夹
            #解压特定文件
            if dir_tmp.endswith("gz") and (dir_tmp.find(cs.Port_week_perfer_name_start) != -1):
                #f = zipfile.ZipFile(dir_tmp, mode="r")
                f = tarfile.open(dir_tmp)
                names = f.getnames()
                for name in names:
                    f.extract(name, path=des_dir)
        else:
            extract_tar_files(dir_tmp,des_dir)
    return 0