35 def FtpRetrieveFile(ftp, filename):  argument
36   ftp.retrbinary('RETR %s' % filename, open(filename, 'wb').write)
54 def FindLatestRemoteTar(ftp, file_prefix):  argument
57   for filename in ftp.nlst():
74 def DownloadAndReplaceLocalFiles(file_prefixes, ftp, local_dir):  argument
78     latest_iana_tar_filename = FindLatestRemoteTar(ftp, file_prefix)
92     FtpRetrieveFile(ftp, latest_iana_tar_filename)
96     FtpRetrieveFile(ftp, signature_filename)
131   ftp = ftplib.FTP('ftp.iana.org')
132   ftp.login()
133   ftp.cwd('tz/releases')
141     new_files = DownloadAndReplaceLocalFiles(['tzdata20', 'tzcode20'], ftp, iana_tools_dir)
144     new_files = DownloadAndReplaceLocalFiles(['tzdata20'], ftp, iana_data_dir)