Add methods to a class at runtime?

[Robert Oschler]

I found the following interesting paragraph regarding Python during a Google
search:

From: Glyph Lefkowitz (glyph at twistedmatrix.com)
Subject: Re: Copy constructors
Newsgroups: comp.lang.python

"One of the eye-popping cool features of Python is the ability to change
code
and have existing instances update to use the new methods automatically. "


Can someone point me to a code snippet shows how to do this?

thx