org-sbe: error when passing strings as parameters to/from Python blocks

org-sbe: error when passing strings as parameters to/from Python blocks

[Karl Voit]

Hi!

I want to test/use Python with org-sbe:

#+NAME: classificationfm
#+BEGIN_SRC python :exports none :var prob :var impact
result = ""
if prob == 'high' and impact == 'high':
    return 'A'
if prob == 'low' and impact == 'high':
    return 'B'
if prob == 'high' and impact == 'low':
    return 'C'
if prob == 'low' and impact == 'low':
    return 'D'
return 'undefined'
#+END_SRC

(Yes, I should move to elif and the Python code might be coded with
less characters in general: this should not be the point here ;-) )

| prob | impact | class  |
|------+--------+--------|
| high | high   | #ERROR |
| low  | high   | #ERROR |
| high | low    | #ERROR |
| low  | low    | #ERROR |
#+TBLFM: @2$3..@>$3='(org-sbe "classificationfm" (prob $1) (impact $2))

I'd expect to get the values of the "class" table column: A, B, C, D
instead of #ERROR.


Reading the manual, I found:
| NOTE: By default, string variable names are interpreted as
| references to source-code blocks, to force interpretation of a
| cell’s value as a string, prefix the identifier a "$" (e.g.,"$$2"
| instead of "$2" or "$@2$2" instead of "@2$2").

Therefore, I tried the following lines ...
#+TBLFM: @2$3..@>$3='(org-sbe "classificationfm" (prob "$1") (impact "$2"))
#+TBLFM: @2$3..@>$3='(org-sbe "classificationfm" (prob $$1) (impact $$2)) 
#+TBLFM: @2$3..@>$3='(org-sbe "classificationfm" (prob "$$1") (impact "$$2")) 
... all with same error in the result.

My setup: Org mode version 9.1.6 on GNU Emacs 26.0.90 and GNU Emacs 25.1.1


I started a reddit thread[1]. In this thread, somebody was posting
this table showing the error:

#+NAME: myfunc
#+BEGIN_SRC python :var n="1"
return "ok"
#+END_SRC

| 10.3 |  9 | -18 | a      | 14 | 11 |  1 |
|   ok | ok |  ok | #ERROR | ok | ok | ok |
#+TBLFM: @2='(org-sbe myfunc (n @1))


However, using the comment from the manual about strings, I
prepended the reference with "$" ...

| 10.3 |  9 | -18 | a  | 14 | 11 |  1 |
|   ok | ok |  ok | ok | ok | ok | ok |
#+TBLFM: @2='(org-sbe mytestfunc (n $@1))

... which now looks OK ;-)


So, back to the initial situation: what is my error or do we have a
bug in Org?


[1] https://www.reddit.com/r/orgmode/comments/b0ll1v/embedding_python_code_in_table_formula/

-- 
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Re: org-sbe: error when passing strings as parameters to/from Python blocks

[Daniel Herzig]

Karl Voit <devnull@Karl-Voit.at> writes:

> Hi!
Hi!
>
> I want to test/use Python with org-sbe:
>
> #+NAME: classificationfm
> #+BEGIN_SRC python :exports none :var prob :var impact
>
> result = ""
> if prob == 'high' and impact == 'high':
>     return 'A'
> if prob == 'low' and impact == 'high':
>     return 'B'
> if prob == 'high' and impact == 'low':
>     return 'C'
> if prob == 'low' and impact == 'low':
>     return 'D'
> return 'undefined'
> #+END_SRC
>
After some trying I found that the variables as set in the source-code
header need standard values set:

#+NAME: classificationfm
#+BEGIN_SRC python :var prob="high" :var impact="high"
  if prob == "high" and impact == "high":
      return "A"
  if prob == "low" and impact == "high":
      return "B"
  if prob == "high" and impact == "low":
      return "C"
  if prob == "low" and impact == "low":
      return "D"
#+END_SRC

If I don't set them I get exactly the same errors as you. Like this I
get the following:

| prob | impact | class |
|------+--------+-------|
| high | high   | A     |
| low  | high   | B     |
| high | low    | C     |
| low  | low    | D     |
#+TBLFM: @2$3..@>$3='(org-sbe classificationfm (prob $$1) (impact $$2))

Evaluation is being asked for each line then.


> (Yes, I should move to elif and the Python code might be coded with
> less characters in general: this should not be the point here ;-) )
>
> | prob | impact | class  |
> |------+--------+--------|
> | high | high   | #ERROR |
> | low  | high   | #ERROR |
> | high | low    | #ERROR |
> | low  | low    | #ERROR |
>
> #+TBLFM: @2$3..@>$3='(org-sbe "classificationfm" (prob $1) (impact $2))
>
> I'd expect to get the values of the "class" table column: A, B, C, D
> instead of #ERROR.
>
>
> Reading the manual, I found:
> | NOTE: By default, string variable names are interpreted as
> | references to source-code blocks, to force interpretation of a
> | cell’s value as a string, prefix the identifier a "$" (e.g.,"$$2"
> | instead of "$2" or "$@2$2" instead of "@2$2").
>
> Therefore, I tried the following lines ...
>
> #+TBLFM: @2$3..@>$3='(org-sbe "classificationfm" (prob "$1") (impact "$2"))
> #+TBLFM: @2$3..@>$3='(org-sbe "classificationfm" (prob $$1) (impact $$2)) 
>
> #+TBLFM: @2$3..@>$3='(org-sbe "classificationfm" (prob "$$1") (impact "$$2")) 
> ... all with same error in the result.
>
>
> My setup: Org mode version 9.1.6 on GNU Emacs 26.0.90 and GNU Emacs 25.1.1
>
>
> I started a reddit thread[1]. In this thread, somebody was posting
> this table showing the error:
>
> #+NAME: myfunc
> #+BEGIN_SRC python :var n="1"
>
> return "ok"
> #+END_SRC
>
> | 10.3 |  9 | -18 | a      | 14 | 11 |  1 |
> |   ok | ok |  ok | #ERROR | ok | ok | ok |
>
> #+TBLFM: @2='(org-sbe myfunc (n @1))
>
>
> However, using the comment from the manual about strings, I
> prepended the reference with "$" ...
>
> | 10.3 |  9 | -18 | a  | 14 | 11 |  1 |
> |   ok | ok |  ok | ok | ok | ok | ok |
>
> #+TBLFM: @2='(org-sbe mytestfunc (n $@1))
>
> ... which now looks OK ;-)
>
>
> So, back to the initial situation: what is my error or do we have a
> bug in Org?
>
>
> [1] https://www.reddit.com/r/orgmode/comments/b0ll1v/embedding_python_code_in_table_formula/


I hope this helps, I'm on orgmode 8.2.1 here.

Cheers,
Daniel

Re: [bug] org-sbe: error when passing strings as parameters to/from Python blocks

[Karl Voit]

Hi Daniel,

* Daniel Herzig <daniel.herzig@outlook.at> wrote:
> Karl Voit <devnull@Karl-Voit.at> writes:
>
> After some trying I found that the variables as set in the source-code
> header need standard values set:
>
> #+NAME: classificationfm
> #+BEGIN_SRC python :var prob="high" :var impact="high"
>   if prob == "high" and impact == "high":
>       return "A"
>   if prob == "low" and impact == "high":
>       return "B"
>   if prob == "high" and impact == "low":
>       return "C"
>   if prob == "low" and impact == "low":
>       return "D"
> #+END_SRC
>
> If I don't set them I get exactly the same errors as you. Like this I
> get the following:
>
>| prob | impact | class |
>|------+--------+-------|
>| high | high   | A     |
>| low  | high   | B     |
>| high | low    | C     |
>| low  | low    | D     |
> #+TBLFM: @2$3..@>$3='(org-sbe classificationfm (prob $$1) (impact $$2))
>
> Evaluation is being asked for each line then.

Thanks for the workaround to circumvent the bug. Now, it's working
with my older Org as well.

Is somebody fixing the bug in Org as well? (Or adding a statement to
the manual?)

-- 
get mail|git|SVN|photos|postings|SMS|phonecalls|RSS|CSV|XML into Org-mode:
       > get Memacs from https://github.com/novoid/Memacs <
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Re: org-sbe: error when passing strings as parameters to/from Python blocks

[Karl Voit]

* Karl Voit <devnull@Karl-Voit.at> wrote:
>
> * Daniel Herzig <daniel.herzig@outlook.at> wrote:
>> Karl Voit <devnull@Karl-Voit.at> writes:
>>
>> After some trying I found that the variables as set in the source-code
>> header need standard values set:
>>
>> #+NAME: classificationfm
>> #+BEGIN_SRC python :var prob="high" :var impact="high"
>>   if prob == "high" and impact == "high":
>>       return "A"
>>   if prob == "low" and impact == "high":
>>       return "B"
>>   if prob == "high" and impact == "low":
>>       return "C"
>>   if prob == "low" and impact == "low":
>>       return "D"
>> #+END_SRC
>>
>> If I don't set them I get exactly the same errors as you. Like this I
>> get the following:
>>
>>| prob | impact | class |
>>|------+--------+-------|
>>| high | high   | A     |
>>| low  | high   | B     |
>>| high | low    | C     |
>>| low  | low    | D     |
>> #+TBLFM: @2$3..@>$3='(org-sbe classificationfm (prob $$1) (impact $$2))
>>
>> Evaluation is being asked for each line then.
>
> Thanks for the workaround to circumvent the bug. Now, it's working
> with my older Org as well.
>
> Is somebody fixing the bug in Org as well? (Or adding a statement to
> the manual?)

On reddit[1] loskutak-the-ptak pointed out that the manual states
that the default value is not optional: [2]

So it is not a bug and it was my own fault from the start. Default
values might be omitted for non-string parameters but it is not
backed by the documentation.

[1] https://www.reddit.com/r/orgmode/comments/b0ll1v/embedding_python_code_in_table_formula/
[2] https://orgmode.org/manual/var.html

-- 
get mail|git|SVN|photos|postings|SMS|phonecalls|RSS|CSV|XML into Org-mode:
       > get Memacs from https://github.com/novoid/Memacs <
Personal Information Management > http://Karl-Voit.at/tags/pim/
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