Replace file name with simple python regex script (for Automator)

I would like to create an automator folder action to rename files that I add in.

Basically, my files are named like that :

SOMETEXT-A00B00-ANOTHERTEXT.extension

To create and run an automator action that rename a file isn't a problem, but I would like to use regex (in Python if possible, 'cause i'm not familiar with apple script or batch) to rename the file like that :

A00B00.extension

Any idea ?