It’s been mentioned here before, but not to be overlooked are kixi stats (https://github.com/MastodonC/kixi.stats) and H2O

as well as Neanderthal (!)

Agree @jsa-aerial. Pandas is ubiquitous, but IMHO not the leader here, nor the first. My favorite is R’s data.table syntax. https://cran.r-project.org/web/packages/data.table/vignettes/datatable-intro.html

data.table is also very fast and flexible