Reading then sending new parts of a log file

[Chuck Connors]

Hey guys.  I'm trying to work up a little program that will send any
new lines written to a file (log file from my home automation
software) to me via instant message.  I've gotten the instant message
sending part figured out using xmpppy.

I've done a few things with Python in the past but I am in no means
more than a beginner/hacker.  Can someone tell me what commands/
modules/etc exist for monitoring and parsing a file for new
information that I can then send to my IM sending function?  I am not
asking for anyone to write the code but merely a push in the right
direction.

Thanks!