In any case, YOU SHOULD NEVER INTRODUCE VARIABLES USING THE __UNDERSCORE__ CONVENTION!
is the "__version__" convention documented somewhere?
This is a trick question, right? :-)
__version__ may not be documented but is in de-facto use. Folks introducing other names (e.g. __author__, __credits__) should really consider a PEP before grabbing a piece of the namespace.
--Guido van Rossum (home page: http://www.python.org/~guido/)