Programming Python, Second Edition

Other Client-Side Tools

So far in this chapter, we have focused on Python’s FTP and email processing tools and have met a handful of client-side scripting modules along the way: ftplib, poplib, smtplib, mhlib, mimetools, urllib, rfc822, and so on. This set is representative of Python’s library tools for transferring and processing information over the Internet, but it’s not at all complete. A more or less comprehensive list of Python’s Internet-related modules appears at the start of the previous chapter. Among other things, Python also includes client-side support libraries for Internet news, Telnet, HTTP, and other standard protocols.

NNTP: Accessing Newsgroups

Python’s nntplib module supports the client-side interface to NNTP -- the Network News Transfer Protocol -- which is used for reading and posting articles to Usenet newsgroups in the Internet. Like other protocols, NNTP runs on top of sockets and merely defines a standard message protocol; like other modules, nntplib hides most of the protocol details and presents an object-based interface to Python scripts.

We won’t get into protocol details here, but in brief, NNTP servers store a range of articles on the server machine, usually in a flat-file database. If you have the domain or IP name of a server machine that runs an NNTP server program listening on the NNTP port, you can write scripts that fetch or post articles from any machine that has Python and an Internet connection. For instance, the script in Example 11-24 ...