Re: Extraneous output from Python code blocks using :session option

[Richard Stanton <stanton@haas.berkeley.edu>]

> On Mar 11, 2015, at 11:29 AM, Kyle Meyer <kyle@kyleam.com> wrote:
> 
> Richard Stanton <stanton@haas.berkeley.edu> wrote:
>> I'm trying to use the :session option so I can import modules, etc.,
>> just once at the beginning of my document, like with am IPython
>> notebook. Unfortunately, the output from these code blocks contains
>> some extraneous characters. For example:
>> 
>> #+BEGIN_SRC python :session :results output
>> a = 2
>> b = 3
>> c = 4
>> print 'a=      ', a
>> print 'b =     ', b
>> print 'a + b = ', a+b
>> #+END_SRC
>> 
>> #+RESULTS:
>> :
>> : >>> >>> a=       2
>> : b =      3
>> : a + b =  5
> 
> I also see this behavior.  I asked the list some time ago [1], but I
> didn't follow up beyond the initial email.
> 
>> How can I stop the production of all those ">" signs (sometimes
>> they're dots), which don't appear if I run the same code block without
>> the :session option?
> 
> I've attached a patch that seems to fix the example you gave and the
> cases from my earlier email.  I don't know enough about babel's
> internals to know if it is a good way to fix it, but at least it might
> serve as a quick fix for you until there is a better solution.
> 
> [1] http://thread.gmane.org/gmane.emacs.orgmode/79014
> 
> From cfa2783e03152871c0d703a6f79e96254dbe6c44 Mon Sep 17 00:00:00 2001
> From: Kyle Meyer <kyle@kyleam.com>
> Date: Wed, 11 Mar 2015 14:17:09 -0400
> Subject: [PATCH] ob-python.el: Strip leading session characters
> 
> * lisp/ob-python.el (org-babel-python-evaluate-session): Strip leading
>  "..." and ">>>" from session output.
> (org-babel-python-strip-session-chars): New function.
> ---
> lisp/ob-python.el | 30 ++++++++++++++++++++----------
> 1 file changed, 20 insertions(+), 10 deletions(-)
> 
> diff --git a/lisp/ob-python.el b/lisp/ob-python.el
> index dd3cc66..0267f22 100644
> --- a/lisp/ob-python.el
> +++ b/lisp/ob-python.el
> @@ -306,16 +306,17 @@ (defun org-babel-python-evaluate-session
>          (results
>           (case result-type
>             (output
> -             (mapconcat
> -              #'org-babel-trim
> -              (butlast
> -               (org-babel-comint-with-output
> -                   (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"))
> +	     (org-babel-python-strip-session-chars
> +	      (mapconcat
> +	       #'org-babel-chomp
> +	       (butlast
> +		(org-babel-comint-with-output
> +		    (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")))
>             (value
>              (let ((tmp-file (org-babel-temp-file "python-")))
>                (org-babel-comint-with-output
> @@ -339,6 +340,15 @@ (defun org-babel-python-read-string (string)
>       (match-string 1 string)
>     string))
> 
> +(defun org-babel-python-strip-session-chars (string)
> +  "Remove leading >>> and ... from Python session output."
> +  (with-temp-buffer
> +    (insert string)
> +    (goto-char (point-min))
> +    (when (looking-at "\\s-*\\(\\(>>> \\)*\\(\\.\\.\\. \\)*\\)")
> +      (delete-region (match-beginning 1) (match-end 1)))
> +    (buffer-string)))
> +
> (provide 'ob-python)
> 
> 
> -- 
> 2.3.2
> 
> 
> —
> Kyle

Many thanks, Kyle. It would be great if this could be fixed in the main code, but I’ll try your patch today.