encode encode encode(infile,outfile,name='-',mode=0666) Reads file-like object infile , by calling infile .read (for a few bytes at a time--the amount of data that UU encodes into a single output line) until end of file (i.e, until a call to infile .read returns an empty string). Then it encodes the data thus read in UU, and writes the encoded text to file-like object outfile . encode also writes a UU begin line before the encoded text, and a UU end line after the encoded text. In the begin line, encode specifies the filename as name and the mode as mode . MIME and Email Format Handling Python supplies the email package to handle parsing, generation, and manipulation of MIME files such as email messages, network news posts, and so on. The Python standard library also contains other modules that handle some parts of these jobs. However, the new email package offers a more complete and systematic approach to these important tasks. I therefore suggest you use package email , not the older modules that partially overlap with parts of email 's functionality. Package email has nothing to do with receiving or sending email; for such tasks, see modules poplib and smtplib , covered in Chapter 18. Instead, package email deals with how you handle messages after you receive them or before you send them.