The rpy2 package is a namespace package. This is the part of that package that
covers the "low-level" interface to R used in rpy2. This provides mappings to
access R's C-API and utilities to do so safely. It is otherwise relatively
easily to crash (segfault) a process by calling R's C-API.

This "low-level" is used by the higher-level (more Pythonic) interface
rpy2.robjects and the extentions for ipython and jupyter notebooks in
rpy2.ipython. It can also be used to implement alternative higher level
interfaces, and with care be used in situation where a minimal interface or
maximum performance is wanted.