How to use Python to programmatically generate part of Sphinx documentation?

Question:

I am using Sphinx to generate the documentation for a project of mine.

In this project, I describe a list of available commands in a yaml file which, once loaded, results in a dictionary in the form {command-name : command-description} for example:

commands = {"copy"  : "Copy the highlighted text in the clipboard",
            "paste" : "Paste the clipboard text to cursor location",
            ...}

What I would like to know, is if there is a method in sphinx to load the yaml file during the make html cycle, translate the python dictionary in some reStructuredText format (e.g. a definition list) and include in my html output.

I would expect my .rst file to look like:

Available commands
==================
The commands available in bla-bla-bla...

.. magic-directive-that-execute-python-code::
   :maybe python code or name of python file here:

and to be converted internally to:

Available commands
==================
The commands available in bla-bla-bla...

copy
  Copy the highlighted text in the clipboard

paste
  Paste the clipboard text to cursor location

before being translated to HTML.

Asked By: mac

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Answers:

Sphinx doesn’t have anything built-in to do what you like. You can either create a custom directive to process your files or generate the reStructuredText in a separate step and include the resulting reStructuredText file using the include directive.

Answered By: devin_s

At the end I find a way to achieve what I wanted. Here’s the how-to:

  1. Create a python script (let’s call it generate-includes.py) that will generate the reStructuredText and save it in the myrst.inc file. (In my example, this would be the script loading and parsing the YAML, but this is irrelevant). Make sure this file is executable!!!
  2. Use the include directive in your main .rst document of your documentation, in the point where you want your dynamically-generated documentation to be inserted:

    .. include:: myrst.inc
    
  3. Modify the sphinx Makefile in order to generate the required .inc files at build time:

    myrst.inc:
        ./generate-includes.py
    
    html: myrst.inc
        ...(other stuff here)
    
  4. Build your documentation normally with make html.

Answered By: mac

Sphinx does support custom extensions that would probably be the best way to do this http://sphinx.pocoo.org/ext/tutorial.html.

Answered By: Matti Pastell

I needed the same thing, so I threw together a new directive that seems to work (I know nothing about custom Sphinx directives, but it’s worked so far):

import sys
from os.path import basename
from StringIO import StringIO

from sphinx.util.compat import Directive
from docutils import nodes

class ExecDirective(Directive):
    """Execute the specified python code and insert the output into the document"""
    has_content = True

    def run(self):
        oldStdout, sys.stdout = sys.stdout, StringIO()
        try:
            exec 'n'.join(self.content)
            return [nodes.paragraph(text = sys.stdout.getvalue())]
        except Exception, e:
            return [nodes.error(None, nodes.paragraph(text = "Unable to execute python code at %s:%d:" % (basename(self.src), self.srcline)), nodes.paragraph(text = str(e)))]
        finally:
            sys.stdout = oldStdout

def setup(app):
    app.add_directive('exec', ExecDirective)

It’s used as follows:

.. exec::
   print "Python code!"
   print "This text will show up in the document"
Answered By: Michael Mrozek

An improvement based on Michael’s code and the built-in include directive:

import sys
from os.path import basename

try:
    from StringIO import StringIO
except ImportError:
    from io import StringIO

from docutils.parsers.rst import Directive    
from docutils import nodes, statemachine

class ExecDirective(Directive):
    """Execute the specified python code and insert the output into the document"""
    has_content = True

    def run(self):
        oldStdout, sys.stdout = sys.stdout, StringIO()

        tab_width = self.options.get('tab-width', self.state.document.settings.tab_width)
        source = self.state_machine.input_lines.source(self.lineno - self.state_machine.input_offset - 1)

        try:
            exec('n'.join(self.content))
            text = sys.stdout.getvalue()
            lines = statemachine.string2lines(text, tab_width, convert_whitespace=True)
            self.state_machine.insert_input(lines, source)
            return []
        except Exception:
            return [nodes.error(None, nodes.paragraph(text = "Unable to execute python code at %s:%d:" % (basename(source), self.lineno)), nodes.paragraph(text = str(sys.exc_info()[1])))]
        finally:
            sys.stdout = oldStdout

def setup(app):
    app.add_directive('exec', ExecDirective)

This one imports the output earlier so that it goes straight through the parser. It also works in Python 3.

Answered By: alex.forencich

I know this question is old, but maybe someone else will find it useful as well.

It sounds like you don’t actually need to execute any python code, but you just need to reformat the contents of your file. In that case you might want to look at sphinx-jinja (https://pypi.python.org/pypi/sphinx-jinja).

You can load your YAML file in the conf.py:

jinja_contexts = yaml.load(yourFileHere)

Then you can use jinja templating to write out the contents and have them treated as reST input.

Answered By: Peter

Not quite the answer you’re after, but perhaps a close approximation: yaml2rst. It’s a converter from YAML to RST. Doesn’t do anything explicitly fancy with the YAML itself, but looks for comment lines (starts with #) and pulls them out into RST chunks (with the YAML going into code-blocks). Allows for a sort-of literate YAML.

Also, the syntax-highlighted YAML is quite readable (heck, it’s YAML, not JSON!).

Answered By: dsz