Pandas, R, and interoperable data frame formats I want to have a single format which is compatible both with R and Python's Pandas (and preferably, other things like Stata and SAS), for which I will not ever need to impute whether things are numbers or dates.

Does such a thing exist? Or has every package got their own system (Pickle, RDS, Stata .dta, .sasb7dat) for the purpose of lock-in?
Is your data in a data frame?  If so, feather is what you're looking for.