Re: Need control over insertion point of variables in code blocks

[Rainer M Krug <r.m.krug@gmail.com>]

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On Fri, Jul 22, 2011 at 9:22 AM, Dirk Scharff
<dirk.scharff@googlemail.com>wrote:

> Hi
>
> i just noticed that variables are assigned in the top of the exported code.
> That can be problematic in some situations:
>
> #+source: the_test
> #+begin_src python :var x=3 :tangle test.py :results output
> from __future__ import division
> print x
> #+end_src
>
>
> tangling results in:
>
> x=3
> from __future__ import division
> print x
>
> The problem with the result is simple:
> SyntaxError: from __future__ imports must occur at the beginning of the
> file
>
> To export this correctly I'd need the possibility to tell org-mode where
> the variables are supposed to be inserted. Is there a way to do this? I
> didn't find a keyword for this in the documentation.
>

For tangling: you could put   from __future__ imports into the :shebang and
use padline ":padline no", i.e.:

#+source: the_test
#+begin_src python :var x=3 :tangle test.py :results output :shebang from
__future__ imports :padline no
print x
#+end_src

which results in

from __future__ imports
print x

Keep in mind, that I have NEVER used python (although I should...).

Cheers,

Rainer

>

A second problem I have at the moment lies with the execution of
> source-blocks in tables. What I'd like to do:
>
> | argument | result |
> |        1 | #ERROR |
> |          |        |
> #+TBLFM: $2=call_the_test(x=$<)
>
> I guess I'm just doing something wrong here. Executing the #+Tblfm results
> in the error: "reference $< not found in buffer". How do I do the reference
> correctly in this case?
>
> You can test both cases in the attached org-file.
>
>
>
>
>
>


-- 
Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation Biology,
UCT), Dipl. Phys. (Germany)

Centre of Excellence for Invasion Biology
Stellenbosch University
South Africa

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