dict to boolean expression, how to?

[Roy Smith]

In article <53db95e6$0$29986$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> eval is almost never the right solution to any problem, and in the very 
> few exceptions, it needs careful handling by an expert to ensure you're 
> not introducing serious security bugs.

Corollary to that rule: All the people who are smart enough to actually 
understand how to use eval() safety, are also smart enough to know not 
to use it.