Accumulating percentile data isn't a very difficult technique. I did the same thing on arduino using nesC so it is surely doable without pandas or numpy.
Completely agree it is easy. Doing it quickly (for Python) is what this is optimized for. We would love a contribution if you have a method for resampling + percentiles that beats numpy.
I will surely give it a look if I have a need for this. Until then, thanks for the contribution and the invitation, and I have nothing against numpy.