When I run the following code block from Emacs org-babel:

#+BEGIN_SRC python :session *Python* :results output

  print("Hello World")


This is what prints out in my *Python* session:

>>> print("Hello World")
Hello World

>>> 'org_babel_python_eoe'
>>> 'org_babel_python_eoe'

How can I get rid of all these extra prompts and org_babel_python_eoe lines?


This patch does it here:

--- ../../../emacs-20190711/lisp/org/ob-python.el   2019-07-09 16:46:01.274976504 +0200
+++ ob-python.el    2019-08-08 21:51:11.185799006 +0200
@@ -294,7 +294,9 @@
 If RESULT-TYPE equals `output' then return standard output as a
 string.  If RESULT-TYPE equals `value' then return the value of the
 last statement in BODY, as elisp."
-  (let* ((send-wait (lambda () (comint-send-input nil t) (sleep-for 0 5)))
+  (let* ((erg "")
+         (filter-re (concat python-shell-prompt-regexp "\\|" "'org_babel_python_eoe'\n" "\\|" "#.+"))
+         (send-wait (lambda () (comint-send-input nil t) (sleep-for 0 5)))
        (tmp-file pp)
@@ -322,16 +324,17 @@
                   (format org-babel-python--exec-tmpfile
-          (mapconcat
-       #'org-trim
-       (butlast
+          ;; (mapconcat
+               ;; #'org-trim
+               ;; (butlast
             (session org-babel-python-eoe-indicator t body)
           (funcall input-body body)
           (funcall send-wait) (funcall send-wait)
           (insert org-babel-python-eoe-indicator)
           (funcall send-wait))
-        2) "\n")))
+               ;; 2) "\n")
+               ))
              (let ((tmp-file (org-babel-temp-file "python-")))
@@ -344,6 +347,10 @@
                    (insert org-babel-python-eoe-indicator)
                    (funcall send-wait)))
                (org-babel-eval-read-file tmp-file))))))
+    (when (listp results)
+      (dolist (ele results)
+        (setq erg (concat erg (ignore-errors (replace-regexp-in-string  filter-re "" ele))))))
+    (setq results erg)
     (unless (string= (substring org-babel-python-eoe-indicator 1 -1) results)
       (org-babel-result-cond result-params

Edit after comment: If you want to apply this, please consider it's only tested WRT examples given here. Make a copy of the original file - maybe undoing is needed. Put the diff-code into some file my-diff.patch. Install the command "patch" if not existing on your system. Call inside the directory where ob-python.el resides: patch < PATH/TO/my-diff.patch. Recompile or remove ob-python.elc - which would be loaded instead of patched source otherwise.

How to run a patched Emacs? Beside the current case: Download Emacs with sources from some gnu-repo. Mention "elc" ".o" in .gitignore. Then do "git init" followed by "git add --all". Now all changes are easily undone by "git checkout FILE".

| improve this answer | |
  • thanks for this! For those of us unfamiliar with the development workflow, can you include the steps for applying this patch in Emacs? – Adam Aug 9 '19 at 18:27

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