You might need to provide some additional information about your setup
(org-version, etc.). This works for me in org 9.1.9.

John

-----------------------------------
Professor John Kitchin
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803
@johnkitchin
http://kitchingroup.cheme.cmu.edu



On Mon, Apr 1, 2019 at 1:07 PM Joao Cortes <joaooneillcortes@outlook.pt>
wrote:

> Consider the following python source block,
>
> #+begin_src python :results output : session :dir ./run
>         import os;
>         cwd = os.getcwd()
>         print(cwd)
> #+end_src
>
> The dir header arg should change the directory used to run the session,
> in this case to the directory "../base/run", where "base" is the parent
> directory the file visited by the current buffer. Instead, I get
> "../base". Is this a bug?
>
> Thank you
> Joao Cortes
>
>