Re: org-babel -- Improper syntax error in session mode?

[Nick Dokos <nicholas.dokos@hp.com>]

Herbert Sitz <hsitz@nwlink.com> wrote:

> Eric Schulte <schulte.eric <at> gmail.com> writes:
> > I can confirm that I see the same behavior.  Also, if I manually type
> > the body of the code block into the session I get the same error output
> > from Python, so I don't believe this is due to a problem with Babel.
> > 
> 
> It appears the problem is that the python session is interactive and is built to
> emit output after each Python "block" (e.g., the 'for' block), before another
> "block" of Python is entered.  If this is the way it's designed then it seems to
> me that it's Babel's obligation to feed the Python blocks to the Python session
> as required and then assemble the output pieces as appropriate.  Or am I missing
> something? -- Herb
> 

Having babel recognize python blocks in order to feed them to the python
interpreter as complete blocks seems a bit too much to me. Of course,
what I think matters little: it's what Eric thinks that matters here.

Having said that, however, I think there *is* a problem:

If you just start the python interpreter and start typing into it:

--8<---------------cut here---------------start------------->8---
x = 1
for i in range(1,5):
  x = x + i
  print x
print "Did it work?"
--8<---------------cut here---------------end--------------->8---

the problem becomes obvious: the interpreter is still in "indented mode"
and complains about the last print, because it is not "properly"
indented.  OTOH, if you exit "indented mode" by pressing another RET
before the final print, the interpreter is happy. This is a kludge used
by the interactive interpreter to accommodate python's reliance on
indentation to delimit block structure.

That however does not work with babel: even if I leave empty lines
between the print x and the last print, the error persists. Apparently,
babel does not send the empty lines to the interpreter. If there is a
bug in babel, it seems to me this is it.

Nick