Thanks for the -Q reminder. I get the same output if I run with emacs -Q
(although I do have to add :results output to each block. I had that set as
a default in my init files).

I had the problem described in the footnote you listed, and that is why I
am using python-mode 5.2, which doesn't have that issue.

John

-----------------------------------
John Kitchin
Associate Professor
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803
http://kitchingroup.cheme.cmu.edu



On Wed, Feb 6, 2013 at 10:10 AM, Myles English <mylesenglish@gmail.com>wrote:

>
> Hi John,
>
> John Kitchin writes:
>
> > I have been trying to use the :session feature of babel for python code
> > blocks. I have noticed a few things that might be areas for
> > improvement. Some issues are related to what I think might be a need for
> > sanitizing the code blocks and the output.
> >
> > I am using (insert (org-version)) 7.9.3a
> > I am using python-mode 5.2 (more modern versions do not work with
> > :session for me)
> >
> > The first small detail is illustrated here:
> >
> > #+BEGIN_SRC python :session
> > a = 5
> >
> > b = 6
> >
> > print a + b
> > #+END_SRC
> >
> > #+RESULTS:
> > :
> > : >>> >>> >>> 11
> >
> > In the output, there are three sets of >>>, due to the two empty
> > lines. Compare this to
> >
> > #+BEGIN_SRC python :session
> > a = 5
> > b = 6
> > print a + b
> > #+END_SRC
> >
> > #+RESULTS:
> > :
> > : >>> 11
> >
> > I think it would be nice to sanitize the python code block sent to the
> > interpreter to eliminate the empty lines, and avoid the multiple >>> in
> > output. It would also be nice to have an option to not print those at
> > all.
> >
> > The second issue is related. The following code does not work for me in
> > :session, but it works fine as a standalone block. The issue is related
> > to the presence of an empty line in the function definition. I like
> > whitespace like this in functions sometimes for readability.
> >
> > #+BEGIN_SRC python :session
> > def func(x):
> >     'doc string'
> >
> >     return x**2
> >
> > print func(2)
> > #+END_SRC
> >
> > #+RESULTS:
> > :
> > : ... >>>   File "<stdin>", line 1
> > :     return x**2
> > :     ^
> > : IndentationError: unexpected indent
> > : >>> None
> >
> > Removing the blank line works fine, but still has some non-pretty
> > output.
> >
> > #+BEGIN_SRC python :session
> > def func(x):
> >     'doc string'
> >     return x**2
> >
> > print func(2)
> > #+END_SRC
> >
> > #+RESULTS:
> > :
> > : ... ... >>> 4
> >
> > One of the ellipsis is due to the doc string.
> > #+BEGIN_SRC python :session
> > def func(x):
> >     return x**2
> >
> > print func(2)
> > #+END_SRC
> >
> > #+RESULTS:
> > :
> > : ... >>> 4
> >
> > Interestingly, this did not work, because there is no empty line after
> > the function definition. So, sanitizing could be tricky.
> >
> > #+BEGIN_SRC python :session
> > def func(x):
> >     'doc string'
> >     return x**2
> > print func(2)
> > #+END_SRC
> >
> > #+RESULTS:
> > :
> > : ... ...   File "<stdin>", line 4
> > :     print func(2)
> > :         ^
> > : SyntaxError: invalid syntax
> >
> > I think if there was a way to strip all the empty lines from the input,
> > it would go a long way to making the output look like what I think most
> > people would expect and want.
> >
> > Anyway, those are the examples I wanted to highlight in this
> > post.
> >
> >
> > 1. Do you see similar behavior, or is this a feature of my setup?
>
> I haven't tried your examples (no time) but you would be able to tell if
> it was a feature of your setup by making a minimum working example and
> starting emacs with 'emacs -Q'.  If you see the thread in the footnote
> it contains such an example.
>
> > 2. Is there any interest in sanitizing the input and output of a
> > python :session to get prettier output? if so, Any hints on where to
> > start with that?
>
> I had some problems recently with :session, there was a short
> discussion[1],
> and last I heard the maintainer of python-mode.el is looking into it.
>
> Myles
>
> Footnotes:
> [1]
> https://lists.gnu.org/archive/html/emacs-orgmode/2013-01/msg00888.html
>
>
>