Christian, I think our patches are quite similar in function. They only allow limited tokens. 

> I consider it a superior solution and a fix for more generic attacks

Mine now still allows **. But it can be easily fixed.

But both our patches still translate a C expression to Python and still suffer from nested ternary operator and different semantics between C and Python, e.g. (2==2==2 as Serhiy notes). :-( I plan to try a simple parser.