* my section 1
#+name: R bloc1
#+begin_src R :results none :session :exports code :comments org
myf <- function(x) {
return(x*x)
    }
#+end_src
* my section 2
** python  !
#+begin_src Python :results none :session :exports code :comments org
def myf(x):
    return x
#+end_src
** python ou Python
#+NAME: python bloc2
#+begin_src python :results none :session :exports code :comments org
def myff(x):
    return(x*x)
#+end_src
