Earlier quoted context omitted.
I've been finding it amazingly useful from the outset. It's like it reads my mind generating whole correct functions just from a small comment or example, and it's great at extrapolating repetitive increments/transformations. Write a small comment telling it what you want and it's uncanny what it can spit out.
I've had the opposite experience so far, though I've admittedly not used it that much yet. I've got this Python fiscal date library at work, and I wanted to add a something like a `strtftime()` method which would replace $P with the period, $Q with the quarter, etc, but treat $$ as a literal $ (so that e.g. $$P would result in $P). Simple enough, but I thought it would be cute to see if I could get copilot to do it f…
Have you tried it on test cases at all?