boilerplate: add .dir-locals.el with emacs python enviroment

The .dir-locals.el set the project's python enviroment for the emacs tasks like
flycheck or jedi.  The py-environment has to be next to <repo>/.dir-locals.el::

    ./local/py3

To setup such an environment build target 'pyenv' or 'pyenvinstall'::

  $ make pyenvinstall

TL;DR

Alternatively create the virtualenv, source it and install jedi + epc
(required by `emacs-jedi <https://tkf.github.io/emacs-jedi>`_)::

    $ virtualenv --python=python3  "--no-site-packages" ./local/py3
    ...
    $ source ./local/py3/bin/activate
    (py3)$ # now install into the activated 'py3' environment ..
    (py3)$ pip install jedi epc
    ...

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
This commit is contained in:
Markus Heiser 2019-11-28 20:08:44 +01:00
parent 796197db2d
commit 62a4b7443f

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.dir-locals.el Normal file
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;;; .dir-locals.el
;;
;; If you get ``*** EPC Error ***`` with this setup in your emacs session,
;; mostly you have jedi-mode enabled but the python enviroment is missed. The
;; python environment has to be next to the ``<repo>/.dir-locals.el`` in::
;;
;; ./local/py3
;;
;; In Emacs, some buffer locals are referencing the project environment:
;;
;; - prj-root --> <repo>/
;; - python-environment-directory --> <repo>/local
;; - python-environment-default-root-name --> py3
;; - python-shell-virtualenv-root --> <repo>/local/py3
;; When this variable is set with the path of the virtualenv to use,
;; `process-environment' and `exec-path' get proper values in order to run
;; shells inside the specified virtualenv, example::
;; (setq python-shell-virtualenv-root "/path/to/env/")
;;
;; To setup such an environment build target 'pyenv' or 'pyenvinstall'::
;;
;; $ make pyenvinstall
;;
;; Alternatively create the virtualenv, source it and install jedi + epc
;; (required by `emacs-jedi <https://tkf.github.io/emacs-jedi>`_)::
;;
;; $ virtualenv --python=python3 "--no-site-packages" ./local/py3
;; ...
;; $ source ./local/py3/bin/activate
;; (py3)$ # now install into the activated 'py3' environment ..
;; (py3)$ pip install jedi epc
;; ...
((nil
. ((fill-column . 80)
))
(python-mode
. ((indent-tabs-mode . nil)
;; project root folder is where the `.dir-locals.el' is located
(eval . (setq-local
prj-root (locate-dominating-file default-directory ".dir-locals.el")))
(eval . (setq-local
python-environment-directory (expand-file-name "./local" prj-root)))
;; use 'py3' enviroment as default
(eval . (setq-local
python-environment-default-root-name "py3"))
(eval . (setq-local
python-shell-virtualenv-root
(concat python-environment-directory
"/"
python-environment-default-root-name)))
;; python-shell-virtualenv-path is obsolete, use python-shell-virtualenv-root!
;; (eval . (setq-local
;; python-shell-virtualenv-path python-shell-virtualenv-root))
(eval . (setq-local
python-shell-interpreter
(expand-file-name "bin/python" python-shell-virtualenv-root)))
(eval . (setq-local
python-environment-virtualenv
(list (expand-file-name "bin/virtualenv" python-shell-virtualenv-root)
;;"--system-site-packages"
"--quiet")))
(eval . (setq-local
pylint-command
(expand-file-name "bin/pylint" python-shell-virtualenv-root)))
;; pylint will find the '.pylintrc' file next to the CWD
;; https://pylint.readthedocs.io/en/latest/user_guide/run.html#command-line-options
(eval . (setq-local
flycheck-pylintrc ".pylintrc"))
;; flycheck & other python stuff should use the local py3 environment
(eval . (setq-local
flycheck-python-pylint-executable python-shell-interpreter))
;; use 'M-x jedi:show-setup-info' and 'M-x epc:controller' to inspect jedi server
;; https://tkf.github.io/emacs-jedi/latest/#jedi:environment-root -- You
;; can specify a full path instead of a name (relative path). In that case,
;; python-environment-directory is ignored and Python virtual environment
;; is created at the specified path.
(eval . (setq-local jedi:environment-root python-shell-virtualenv-root))
;; https://tkf.github.io/emacs-jedi/latest/#jedi:server-command
(eval .(setq-local
jedi:server-command
(list python-shell-interpreter
jedi:server-script)
))
;; jedi:environment-virtualenv --> see above 'python-environment-virtualenv'
;; is set buffer local! No need to setup jedi:environment-virtualenv:
;;
;; Virtualenv command to use. A list of string. If it is nil,
;; python-environment-virtualenv is used instead. You must set non-nil
;; value to jedi:environment-root in order to make this setting work.
;;
;; https://tkf.github.io/emacs-jedi/latest/#jedi:environment-virtualenv
;;
;; (eval . (setq-local
;; jedi:environment-virtualenv
;; (list (expand-file-name "bin/virtualenv" python-shell-virtualenv-root)
;; ;;"--python"
;; ;;"/usr/bin/python3.4"
;; )))
;; jedi:server-args
)))