calling R from python using rpy2

Question

I am trying to shift from R to Python for big data analytics. But since I still need some of the excellent statistical functions present in R, I invoke them in Python using rpy2.

My question is does rpy2 has any limitation regarding calling R functions. And can we convert a python script into an executable file , when we are using R inside python ?

Also can we call custom functions from R to Python using the same library?