csv - how to parse a string, not a file?

[Alex Hunsley]

I've using the csv module to parse a string, not a file.
So how do I make a string look like a file so I can call csv.reader() 
with it?

An an example, I'd like to call something like:

csvReader = csv.reader("1,2,3,4")

.. but this direct attempt won't work as it expects a file or a handle...

thanks
alex