Thanks David, I agree that my assumption that the local valiables were not being replaced is not really what was going on there.

I also agree that, while this might not strictly classify as a bug, it's probably not the most helpful/useful way that "from ." could be implemented for __main__. Why does it act different than in modules?

I have reproduced my original ploblem in a simplified scenario, for which I will raise a new bug.

Thanks