Language specific default headers for code blocks in org-mode

Posted January 26, 2014 at 12:06 PM | categories: emacs-lisp, org-mode | tags:

I use code blocks in org-mode a lot. I usually code in Python, and in Python I usually write code that prints output which I want to see. So I almost always want the code blocks to return the output, and not the value of the last function. I have set my default header args like this: 

org-babel-default-header-args
(:exports . both) (:results . replace output) (:session . none) (:cache . no) (:noweb . no) (:hlines . no) (:tangle . no)

However, I would prefer that emacs-lisp blocks use value for the results. I know I can get that by putting :results value in the code block header, but that annoys me. I learned today from http://orgmode.org/worg/org-contrib/babel/header-args.html that you can make language specific default headers!

This code in my init file sets emacs-lisp specific default headers: 

(setq org-babel-default-header-args:emacs-lisp 
      (cons '(:results . "value")
            (assq-delete-all :results org-babel-default-header-args)))

That way I do not have type :results value at the top of every elisp block. Of course, if I want the output I could specify :results output in the block. 

org-babel-default-header-args:emacs-lisp
(:results . value) (:exports . both) (:session . none) (:cache . no) (:noweb . no) (:hlines . no) (:tangle . no)

Problem solved!

On a related note, I find I write so many blocks of python and elisp I added these templates: 

;; add <p for python expansion
(add-to-list 'org-structure-template-alist
             '("p" "#+BEGIN_SRC python\n?\n#+END_SRC" "<src lang=\"python\">\n?\n</src>"))

;; add <el for emacs-lisp expansion
(add-to-list 'org-structure-template-alist
             '("el" "#+BEGIN_SRC emacs-lisp\n?\n#+END_SRC" "<src lang=\"emacs-lisp\">\n?\n</src>"))

I probably could have also coded the :results header into those too. They add a tidbit of convenience so I do not have to type python or emacs-lisp after expanding a source block with <s.

Copyright (C) 2014 by John Kitchin. See the License for information about copying.

org-mode source

Org-mode version = 8.2.5g

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