emacs-orgmode@gnu.org archives
 help / color / mirror / code / Atom feed
From: "Berry, Charles" <ccberry@health.ucsd.edu>
To: Norman Walsh <ndw@nwalsh.com>
Cc: emacs-orgmode <emacs-orgmode@gnu.org>
Subject: Re: “Literate” python?
Date: Fri, 29 Nov 2019 19:22:54 +0000	[thread overview]
Message-ID: <8758420C-4BEB-45F6-ADB9-D141DD917EB6@ucsd.edu> (raw)
In-Reply-To: <m2d0daa7qe.fsf@nwalsh.com>



> On Nov 29, 2019, at 9:54 AM, Norman Walsh <ndw@nwalsh.com> wrote:
> 
> Hi,
> 
> I’ve seen a couple of pointers recently to using Org mode and tangle
> to write more literate Emacs configurations. I use Org+babel all the
> time to write “interactive” documents, so I thought I’d try out tangle
> from Org.
> 
> I didn’t want to start with something as comlicated as my Emacs
> config :-) so I figured I’d kick the tires with a small python
> program. That did not end well.
> 
> Consider:
> 
> #+TITLE: Python literate programming
> #+OPTIONS: html-postamble:nil
> 
> It starts off as a completely standard Python3 program.
> 
> ---%<------------------------------------------------------
> #+BEGIN_SRC python :tangle yes :weave no
> #!/usr/bin/env python3
> 
> #+END_SRC
> 
> It defines ~a~.
> 
> #+BEGIN_SRC python :tangle yes
> def a():
>    print("a")
> 
> 
> #+END_SRC
> 
> And ~b~.
> 
> #+BEGIN_SRC python :tangle yes
> def b():
>    print("b")
> 
> 
> #+END_SRC
> 
> Now ~c~ is a little more complicated:
> 
> #+BEGIN_SRC python :tangle yes
> def c():
>   print("c")
> #+END_SRC
> 
> Not only does ~c~ print “c”, it calls ~a()~ and ~b()~.
> 
> #+BEGIN_SRC python :tangle yes
>   b()
>   a()
> #+END_SRC
> 
> Finally, make it importable. Not that you’d want to.
> 
> #+BEGIN_SRC python :tangle yes
> if __name__ == "__main__":
>    main()
> #+END_SRC
> --->%------------------------------------------------------
> 
> That’s the script. It weaves into HTML more-or-less ok (there’s a
> weird black box at the front of indented lines, but I can come back to
> that later).
> 
> It’s a complete mess when tangled.
> 
> The extra blank lines between functions (to make pylint happy with
> some PEP guideline) have disappeared. I guess I could live with that,
> but the complete failure to preserve indention in the penultimate code
> block is a show stopper:

[results of tangling deleted]

A couple of things might help.

First, use the :noweb-ref argument to mark each of the code blocks you wish to tangle.  

Say `:noweb-ref tangleyes'. Or some more evocative name.

Remove the `:tangle yes' from each of those. Then, add a code block that has only `<<tangleyes>>' in it and tangle it.

#+begin_src python :noweb yes :tangle yes
<<tangleyes>>
#+end_src

The remaining problem (as you will see) is the indentation. Fix this by adding the `-i' flag to the penultimate code block, viz.

#+BEGIN_SRC python -i :noweb-ref tangleyes
   b()
   a()
#+END_SRC

See 12.6 Literal Examples and 15.10 Noweb Reference Syntax in the manual.

HTH,

Chuck



  reply	other threads:[~2019-11-29 19:23 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-29 17:54 Norman Walsh
2019-11-29 19:22 ` Berry, Charles [this message]
2019-11-29 21:09   ` Norman Walsh
2019-11-29 19:30 ` George Mauer
2019-11-29 21:10   ` Norman Walsh
2019-11-29 22:32 ` Diego Zamboni
2019-11-30  0:25   ` Norman Walsh

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.orgmode.org/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=8758420C-4BEB-45F6-ADB9-D141DD917EB6@ucsd.edu \
    --to=ccberry@health.ucsd.edu \
    --cc=emacs-orgmode@gnu.org \
    --cc=ndw@nwalsh.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs/org-mode.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).