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