This use of :prologue appeared to me to be very useful.  But for some 
reason when I try it out it does not work for me.  I just get a message 
that the code block produced no output and that 'np' is not defined.  
Just to check, when I put the import statements directly within my code 
block it works fine.

I am running:  Org mode version 9.3.7 (9.3.7-16-g521d7f-elpa

Any idea what I'm doing wrong?


On 8/6/20 2:12 PM, Ken Mankoff wrote:
> Actual example:
>
>
> * Prologue test
> :PROPERTIES:
> :header-args:python+: :prologue "import numpy as np; import os"
> :END:
>
> #+BEGIN_SRC python :results output
> print(np.__version__)
> #+END_SRC
>
> #+RESULTS:
> : 1.18.4
>
>
>
>
> On Wed, Aug 5, 2020 at 3:03 PM Ken Mankoff <mankoff@gmail.com 
> <mailto:mankoff@gmail.com>> wrote:
>
>     What about using :pre or :prologue and setting it at the header or
>     document level?
>
>     Please excuse brevity. Sent from tiny pocket computer with
>     non-haptic-feedback keyboard.
>
>     On Wed, Aug 5, 2020, 14:22 George Mauer <gmauer@gmail.com
>     <mailto:gmauer@gmail.com>> wrote:
>
>         Use case:
>
>         I'm using ob-racket
>         <https://github.com/togakangaroo/ob-racket> but this would
>         apply just as well to a few other workflows I have with python
>         or js.
>
>         I would like to write a helper function in a src block and
>         then automatically have access to it in other src blocks
>         further down the document. I don't really want a stateful
>         session (nor does ob-racket support sessions) so I essentially
>         want the equivalent of automatically including it everywhere
>         so I don't have to type it out all the time (and have it screw
>         up syntax coloring/indentation).
>
>         Is this currently possible? Does anyone have any ideas for how
>         to extend things so it is?
>