PyCLIPS is an extension module that embeds full CLIPS functionality in Python applications.

PyCLIPS is an extension module that embeds full CLIPS functionality in Python applications. This means that you can provide Python with a strong, reliable, widely used and well documented inference engine.

Actually, CLIPS is often taken as "reference implementation" of an expert systems shell by many programmers and groups involved in AI developement. It has a forward chaining rule-based inference system, as well as all imperative and object-oriented constructs that allow controlling the execution flow.