Python压缩文件

import zipfile, osdef zip_dir(dirname,zipfilename):    filelist = []    if os.path.isfile(dirname):        filelist.append(dirname)    else :        for root, dirs, files in os.walk(dirname):            for name in files:                filelist.append(os.path.join(root, name))    zf = zipfile.ZipFile(zipfilename, "w", zipfile.ZIP_STORED, allowZip64=True)    for tar in filelist:        arcname = tar[len(dirname):]        #print arcname        zf.write(tar, arcname)    zf.close()