  We present RUBIS (Rotation code Using Barotropy conservation over
Isopotential Surfaces), a fully Python-based centrifugal deformation program
available at \url{https://github.com/pierrehoudayer/RUBIS}. The code has been
designed to calculate the centrifugal deformation of stars and planets
resulting from a given cylindrical rotation profile, starting from a
spherically symmetric non-rotating model.
  The underlying assumption in RUBIS is that the relationship between density
and pressure is preserved during the deformation process. This leads to many
procedural simplifications. For instance, RUBIS only needs to solve Poisson'
equation, either in spheroidal or spherical coordinates depending on whether
the 1D model has discontinuities or not.
  We present the benefits of using RUBIS to deform polytropic models and more
complex barotropic structures, thus providing, to a certain extent, insights
into baroclinic models. The resulting structures can be used for a wide range
of applications, including the seismic study of models. Finally, we illustrate
how RUBIS is beneficial specifically in the analysis of Jupiter's gravitational
moments, thanks to its ability to handle discontinuous models while retaining a
high accuracy compared to current methods.
