After reading this paragraph, I started seriously questioning the objectiveness of the comparison.

>By contrast, just now I tried to find nearest-neighbor code for Python and at least with my cursory search, came up empty-handed; there was just one implementation that described itself as simple and straightforward, nothing fast.

> The following searches in PyPI turned up nothing: log-linear model; Poisson regression; instrumental variables; spatial data; familywise error rate; etc.

This is not how you search for things. Usually I search on google for "poisson regression scipy" if I'm looking for poisson regression.