contrib/babel/lisp/langs/org-babel-python.el

   1 ;;; org-babel-python.el --- org-babel functions for python evaluation
   2
   3 ;; Copyright (C) 2009 Eric Schulte
   4
   5 ;; Author: Eric Schulte
   6 ;; Keywords: literate programming, reproducible research
   7 ;; Homepage: http://orgmode.org
   8 ;; Version: 0.01
   9
  10 ;;; License:
  11
  12 ;; This program is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 3, or (at your option)
  15 ;; any later version.
  16 ;;
  17 ;; This program is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21 ;;
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  25 ;; Boston, MA 02110-1301, USA.
  26
  27 ;;; Commentary:
  28
  29 ;; Org-Babel support for evaluating python source code.
  30
  31 ;;; Code:
  32 (require 'org-babel)
  33 (require 'python)
  34
  35 (org-babel-add-interpreter "python")
  36
  37 (add-to-list 'org-babel-tangle-langs '("python" "py" "#!/usr/bin/env python"))
  38
  39 (defun org-babel-execute:python (body params)
  40   "Execute a block of Python code with org-babel.  This function is
  41 called by `org-babel-execute-src-block' via multiple-value-bind."
  42   (message "executing Python source code block")
  43   (let ((full-body (concat
  44                     (mapconcat ;; define any variables
  45                      (lambda (pair)
  46                        (format "%s=%s"
  47                                (car pair)
  48                                (org-babel-python-var-to-python (cdr pair))))
  49                      vars "\n") "\n" (org-babel-trim body) "\n")) ;; then the source block body
  50         (session (org-babel-python-initiate-session session)))
  51     (org-babel-python-evaluate session full-body result-type)))
  52
  53 (defun org-babel-prep-session:python (session params)
  54   "Prepare SESSION according to the header arguments specified in PARAMS."
  55   (let* ((session (org-babel-python-initiate-session session))
  56          (vars (org-babel-ref-variables params))
  57          (var-lines (mapcar ;; define any variables
  58                      (lambda (pair)
  59                        (format "%s=%s"
  60                                (car pair)
  61                                (org-babel-python-var-to-python (cdr pair))))
  62                      vars)))
  63     (org-babel-comint-in-buffer session
  64       (mapc (lambda (var)
  65               (move-end-of-line 1) (insert var) (comint-send-input nil t)
  66               (org-babel-comint-wait-for-output session)) var-lines))))
  67
  68 ;; helper functions
  69
  70 (defun org-babel-python-var-to-python (var)
  71   "Convert an elisp var into a string of python source code
  72 specifying a var of the same value."
  73   (if (listp var)
  74       (concat "[" (mapconcat #'org-babel-python-var-to-python var ", ") "]")
  75     (format "%S" var)))
  76
  77 (defun org-babel-python-table-or-string (results)
  78   "If the results look like a table, then convert them into an
  79 Emacs-lisp table, otherwise return the results as a string."
  80   (org-babel-read
  81    (if (string-match "^\\[.+\\]$" results)
  82        (org-babel-read
  83         (replace-regexp-in-string
  84          "\\[" "(" (replace-regexp-in-string
  85                     "\\]" ")" (replace-regexp-in-string
  86                                ", " " " (replace-regexp-in-string
  87                                          "'" "\"" results)))))
  88      results)))
  89
  90 (defvar org-babel-python-buffers '(:default . nil))
  91
  92 (defun org-babel-python-session-buffer (session)
  93   (cdr (assoc session org-babel-python-buffers)))
  94
  95 (defun org-babel-python-initiate-session-by-key (&optional session)
  96   "If there is not a current inferior-process-buffer in SESSION
  97 then create.  Return the initialized session."
  98   (save-window-excursion
  99     (let* ((session (if session (intern session) :default))
 100            (python-buffer (org-babel-python-session-buffer session)))
 101       (run-python)
 102       (setq org-babel-python-buffers (cons (cons session python-buffer)
 103                                            (assq-delete-all session org-babel-python-buffers)))
 104       session)))
 105
 106 (defun org-babel-python-initiate-session (&optional session)
 107   (unless (string= session "none")
 108     (org-babel-python-session-buffer (org-babel-python-initiate-session-by-key session))))
 109
 110 (defvar org-babel-python-last-value-eval "_"
 111   "When evaluated by Python this returns the return value of the last statement.")
 112 (defvar org-babel-python-eoe-indicator "'org_babel_python_eoe'"
 113   "Used to indicate that evaluation is has completed.")
 114 (defvar org-babel-python-wrapper-method
 115   "
 116 def main():
 117 %s
 118
 119 open('%s', 'w').write( str(main()) )")
 120
 121 (defun org-babel-python-evaluate (buffer body &optional result-type)
 122   "Pass BODY to the Python process in BUFFER.  If RESULT-TYPE equals
 123 'output then return a list of the outputs of the statements in
 124 BODY, if RESULT-TYPE equals 'value then return the value of the
 125 last statement in BODY, as elisp."
 126   (if (not session)
 127       ;; external process evaluation
 128       (save-window-excursion
 129         (case result-type
 130           (output
 131            (with-temp-buffer
 132              (insert body)
 133              ;; (message "buffer=%s" (buffer-string)) ;; debugging
 134              (shell-command-on-region (point-min) (point-max) "python" 'replace)
 135              (buffer-string)))
 136           (value
 137            (let ((tmp-file (make-temp-file "python-functional-results")))
 138              (with-temp-buffer
 139                (insert
 140                 (format
 141                  org-babel-python-wrapper-method
 142                  (let ((lines (split-string
 143                                (org-remove-indentation (org-babel-trim body)) "[\r\n]")))
 144                    (concat
 145                     (mapconcat
 146                      (lambda (line) (format "\t%s" line))
 147                      (butlast lines) "\n")
 148                     (format "\n\treturn %s" (last lines))))
 149                  tmp-file))
 150                ;; (message "buffer=%s" (buffer-string)) ;; debugging
 151                (shell-command-on-region (point-min) (point-max) "python"))
 152              (org-babel-python-table-or-string
 153               (with-temp-buffer (insert-file-contents tmp-file) (buffer-string)))))))
 154     ;; comint session evaluation
 155     (org-babel-comint-in-buffer buffer
 156       (let* ((raw (org-babel-comint-with-output buffer org-babel-python-eoe-indicator t
 157                     ;; for some reason python is fussy, and likes enters after every input
 158                     (mapc (lambda (statement) (insert statement) (comint-send-input nil t))
 159                           (split-string (org-babel-trim full-body) "[\r\n]+"))
 160                     (comint-send-input nil t) (comint-send-input nil t)
 161                     (insert org-babel-python-last-value-eval)
 162                     (comint-send-input nil t)
 163                     (insert org-babel-python-eoe-indicator)
 164                     (comint-send-input nil t)))
 165              (results (delete org-babel-python-eoe-indicator
 166                               (cdr (member org-babel-python-eoe-indicator
 167                                            (reverse (mapcar #'org-babel-trim raw)))))))
 168         (setq results (mapcar #'org-babel-python-read-string results))
 169         (case result-type
 170           (output (org-babel-trim (mapconcat #'identity (reverse (cdr results)) "\n")))
 171           (value (org-babel-python-table-or-string (org-babel-trim (car results)))))))))
 172
 173 (defun org-babel-python-read-string (string)
 174   "Strip 's from around ruby string"
 175   (if (string-match "'\\([^\000]+\\)'" string)
 176       (match-string 1 string)
 177     string))
 178
 179 (provide 'org-babel-python)
 180 ;;; org-babel-python.el ends here