On Sep 8, 2017 4:06 PM, "Eric Snow" <ericsnowcurrently@gmail.com> wrote: run(code): Run the provided Python code in the interpreter, in the current OS thread. If the interpreter is already running then raise RuntimeError in the interpreter that called ``run()``. The current interpreter (which called ``run()``) will block until the subinterpreter finishes running the requested code. Any uncaught exception in that code will bubble up to the current interpreter. This phrase "bubble up" here is doing a lot of work :-). Can you elaborate on what you mean? The text now makes it seem like the exception will just pass from one interpreter into another, but that seems impossible – it'd mean sharing not just arbitrary user defined exception classes but full frame objects... -n