In case anyone is interested: Gideon Smeding of the University of Utrecht has written a masters' thesis titled "An executable operational semantics for Python". It is actually a formal semantics for a Python subset called minpy. Per the blurb, the semantics are described in literate Haskell that is compiled to an interpreter as well as a formal specification. Somehow there has to be a a reference about "unless you're Dutch" to be made about this ;-).
Further info is at: http://gideon.smdng.nl/2009/01/an-executable-operational-semantics-for-python/ I found this link via the Haskell Weekly News, http://sequence.complete.org . -- http://mail.python.org/mailman/listinfo/python-list
