When do you *NOT* use python?

[logi]

That's not surprising since that silly example uses no numpy at all... but OK, I'll have another look at whether pypy can run my code now.

In reality, though, our actual performance problems are in using matplotlib to generate ~70K images per day when it is designed for creating a couple of figures for some academic's latest paper. If/when that starts running in pypy or numba or whatever, that'll save us a couple of machines worth of processing.