What does 'is' do?

[Delaney, Timothy C (Timothy)]

Derek Fountain wrote:

> I recently saw a use of 'is' in a piece of Python code. I was trying
> to find out what it does. I can't find it in the online docs. I have
> the "Python in a Nutshell" book and that mentions it as a keyword,
> but I can't find a description of it in there either. It's not in the
> index. 
> 
> Can someone tell me where to look?

http://docs.python.org/lib/comparisons.html

Tim Delaney