Re: ob-python: import local package into a session

[Tom Gillespie <tgbugs@gmail.com>]

I have also been dissatisfied with the current options for making
local python libraries accessible in certain org files. The amount of
setup that is required outside the org file itself was too large,
especially if you want someone else who is not intimately familiar
with python to be able to use it. My old solution was to modify the
PYTHONPATH environment variable for the whole Emacs process. However,
after a bit of digging inspired by this thread I now have a solution
that is entirely local: advise ~org-babel-execute:python~ to set a new
PYTHONPATH via the ~process-environment~ dynamic variable and set that
from a buffer local variable for the local additions to PYTHONPATH
along with getenv PYTHONPATH. A working example below. Best!
Tom

#+name: orgstrap
#+begin_src elisp :results none :noweb noexport
(defvar-local local-python-path nil)

(defun advise--obe-python-path (command &rest args)
  (let ((process-environment
         (or (and local-python-path
                  (cons
                   (format
                    "PYTHONPATH=%s"
                    (concat local-python-path (getenv "PYTHONPATH")))
                   process-environment))
             process-environment)))
    (apply command args)))

(advice-add #'org-babel-execute:python :around
            #'advise--obe-python-path)

(setq-local local-python-path (concat default-directory "code:"))
#+end_src

On Tue, Nov 24, 2020 at 9:26 AM Jack Kamm <jackkamm@gmail.com> wrote:
>
> Joost Kremers <joostkremers@fastmail.fm> writes:
>
> > I haven't really considered the option to install the utility functions as a
> > package in the virtual environment, because I expect to change and develop those
> > functions together with the rest of the project. If it were a separate package,
> > I'd need to reinstall it every time I make changes to it, which will probably
> > happen often.
>
> If you install the package using either "python setup.py develop", or
> "pip install -e", then Python will install your code via symlinks
> instead of copying, so then you don't have to worry about reinstalling
> every time you make an edit.
>
> To switch between venv's in emacs, I use pyvenv:
> https://github.com/jorgenschaefer/pyvenv
>