python operational semantics paper

[Paul Rubin]

This looks kind of interesting.

http://cs.brown.edu/~sk/Publications/Papers/Published/pmmwplck-python-full-monty/

Abstract

We present a small-step operational semantics for the Python programming
language. We present both a core language for Python, suitable for tools
and proofs, and a translation process for converting Python source to
this core. We have tested the composition of translation and evaluation
of the core for conformance with the primary Python implementa- tion,
thereby giving confidence in the fidelity of the seman- tics. We briefly
report on the engineering of these compo- nents. Finally, we examine
subtle aspects of the language, identifying scope as a pervasive concern
that even impacts features that might be considered orthogonal.