On a more relevant note, thanks for sharing this. It's always nice to read an explanation from somebody patient enough to not skip over a bunch of steps in the middle and avoid losing newbs like me.
"That" and "which" are apparently interchangeable on the other side of the pond, and the author is from Imperial College London.
On a more relevant note, I agree, this is a great article. :) (I'd already known in theory how decorators work, but this was a very clear presentation, and I hadn't quite thought through the part about only needing a reference to the unmodified function, so it was useful to see that trick spelled out.)
On a more relevant note, thanks for sharing this. It's always nice to read an explanation from somebody patient enough to not skip over a bunch of steps in the middle and avoid losing newbs like me.