While not mentioned in the article, Julia is indeed an interesting one, which I even think is probably more suitable as an actual *Python* substitute than Nim.
The reason it wasn't included is just a matter of my writing style I guess. I first aimed to answer the question of "Is Nim A Python Substitute?" rather than "What's the Best Python Substitute?".
Once that was answered, I placed Nim in what I called in the article the performant-yet-nicer-than-C++ niche, which is why Go earned that honorable mention.
If I were to truly discuss Python alternatives, Julia would be up there.