Include my markdown README into Sphinx

Question

I would like to include my project's README.md into my Sphinx documentation like in Can sphinx link to documents that are not located in directories below the root document? - which is that in the resulting Sphinx html documentation I click on a link in the table of contents on the welcome page and get to the README.md.

For that a document readme_link.rst is created which contains the lines

Readme File
-----------

.. include:: ../../README.md

and I add the line

README <readme_link>

into the toctree of index.rst. Going with that, my README.md is not parsed as Markdown, but just printed onto the page as-is-text.

I thought an alternative idea might be to have a markdown file readme_link.md instead, but there is no way to include files with markdown.

How can I have my README.md parsed as markdown?

(Of course I don't want to rewrite it as .rst.)

Why m2r is not working

I tried to follow Render output from markdown file inside .rst file, but this is not working. My README.md has some headings like

# First heading

some text

## Second heading 1

some text

## Second heading 2

some text

and I get the error WARNING: ../README.md:48: (SEVERE/4) Title level inconsistent:. I understand from What does "Title level inconsistent" mean? that I need to use other symbols - but reading into them I realized that the answer refers to rst symbols. That would mean that my markdown readme actually wasn't transformed into rst.

PS: Someone else who tried something like that is https://muffinresearch.co.uk/selectively-including-parts-readme-rst-in-your-docs/

Solution 1

You need to edit your readme_link.rst as follows:

Readme File
===========

.. mdinclude:: ../../README.md

Note that the section header is designated with = characters rather than - characters.

There are two factors that contribute to that.

How include works

Standard include (not mdinclude) actually reads the content of the source file and simply copies the raw text in place of the directive. M2R's mdinclude first converts the source Markdown text to rst, and then, like include, copies that test in place of the directive.

Therefore, by the time the rst document is parsed, you have one complete rst document from both the parent and included files. That one complete document needs to be a valid rst document, which takes us to the second point...

Header levels must be consistent.

As a reminder, the reStructuredText Spec explains:

Rather than imposing a fixed number and order of section title adornment styles, the order enforced will be the order as encountered. The first style encountered will be an outermost title (like HTML H1), the second style will be a subtitle, the third will be a subsubtitle, and so on.

...

All section title styles need not be used, nor need any specific section title style be used. However, a document must be consistent in its use of section titles: once a hierarchy of title styles is established, sections must use that hierarchy.

Therefore, the header levels in the included child must be consistent with the header levels in the parent. As M2R generates a rst document, you (as the end user) don't get to specificity which character is used to define each section level. Therefore, to maintain consistency, you need to use the scheme defined by M2R:

• Rst heading marks are currently hard-coded and unchangeable.
  • H1: =, H2: -, H3: ^, H4: ~, H5: ", H6: #

As you can see, level 1 headers use the = character and level 2 headers use the - character. Therefore, the same scheme needs to be used in the parent readme_link.rst file (you were using the reverse).

An alternate solution

The reStructuredText spec also states:

Underline-only adornment styles are distinct from overline-and-underline styles that use the same character.

Therefore, you could use overline-and-underline styles in your parent document and it wouldn't matter which characters you used for which level as M2R only appears to use underline-only styles. So this would have worked as well:

-----------
Readme File
-----------

.. mdinclude:: ../../README.md

This has the added benefit (or negative -- depending on your point of view) that all headers in the included child document will now be one level lower that they would on their own. Therefore, the child is more semantically "nested" in the parent (more than one h1 in a single HTML document is often considered to not be semantic although it is technically "valid"). Of course, this may or may not be what you want, which is why it is labeled an "alternate solution".

Solution 2

There is an alternative approach, if you only want to include a markdown document in your project as a separate file (and don't need to embed the contents of that file into an .rst file):

1. Ensure you have the necessary prerequisites

(These steps are also requisite for the accepted answer.)

1.1 Ensure you have the markdown renderer installed:

$ pip install -U sphinx>=1.8.3 recommonmark>=0.5.0

1.2 Add recommonmark to the list of extensions in conf.py

See the documentation for canonical instructions on this.

1.3 Make a symlink to your markdown file

$ cd docs             # or docs/source
$ ln -s ../README.md  # or to ../../README.md if using docs/source

2. Include the required markdown file in your docs

Link the file in your toctree:

.. toctree::
   :maxdepth: 2
   :caption: Contents:

   source/README.md

Solution 3

If you also come across the error TypeError: add_source_parser(), here is the solution:

Using m2r2 instead of m2r. That is,

in the file readme_link.rst, we write

.. mdinclude:: ../README.md

and in the file conf.py we add

extensions = [
    # ...
    'm2r2'
]
# ...

# source_suffix = '.rst'
source_suffix = ['.rst', '.md']

Solution 4

I've installed myst-parser extension and tried to include a Markdown file into a .rst file

.. include:: README.md

It is not being parsed. Added :parser: markdown option, but docutils complains that "recommonmark" extension is not installed. I've found a way to include parsed md file:

.. include:: README.md
   :parser: myst_parser.sphinx_

Solution 5

The simplest way is to use MyST-Parser, which happens to be the extension now recommended in Sphinx docs for handling Markdown. No need for m2r.

MyST-Parser allows reStructuredText-style directives to be embedded in Markdown files. We'll use that feature to include your Markdown README.md into a placeholder Markdown file that will then get rendered to HTML.

In conf.py:

extensions = [
    # ...
    "myst_parser"
]

Your readme_link file should then be in Markdown format instead of reStructuredText i.e. create a readme_link.md file containing an include directive:

```{include} ../../README.md
```

This directive simply dumps the contents of README.md into readme_link.md which is itself in Markdown, so there's no need to do any conversion to reStructuredText at this point. readme_link.md will get rendered into HTML along with all other source files thanks to the myst_parser extension.

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Comments

[J_yang]

I think linking might be problematic for version control. Is there a way to directly use relatively path? I tried ../README.md . But Sphinix couldn't find it.

[chrisinmtown]

For step 1.2, would you please show exactly how to add recommonmark to the list of extensions in conf.py?

[Shon]

@chrisinmtown I added a link to the relevant section of the documentation. I don't want to "hardcode" in the configuration here, lest the answer become stale when they change something.

[chrisinmtown]

Anything can change at anytime :) this kind of hint would have really helped: extensions = [ 'recommonmark' ]

[Shon]

Do you think that now, with the official documentation just a click away, future readers in your position will be adequately guided?

[pjk]

mdinclude is no longer supported

[Waylan]

@pjk do you have a source for that claim? It is still mentioned in the docs for M2R.

[pjk]

based on github.com/sphinx-doc/sphinx/issues/7420#issuecomment-609814‌​898 and github.com/sparkfun/Qwiic_Template_Py/issues/1 . m2r2 seems to work for me. couldn't get m2r to get my work done.

[Waylan]

Ah, I see, it hasn't been updated to work with Sphinx 3. It appears that m2r2 is an updated fork which does work with Sphinx 3.

[Vineet]

m2r2 isn't able to import images from README. Any hints why it can be so ?

[DankMasterDan]

This is the correct answer since 2020 when myst_parser officially recomended

[jmcker]

:parser: myst_parser.sphinx_ was key for me. Parsing was not working until I added it.

[Sam Martin]

I was having an issue with this where it was complaining that unknown option: "parser".. Turns out I had a version of docuitils prior to 0.17 and upgrading it solved the problem.

[Chris Sewell]

This solution is now in the documentation :) myst-parser.readthedocs.io/en/latest/sphinx/…

[CharlesG]

This is the cleanest solution to include any markdown file in you rst files and combine both syntaxes easily.

[Savvy Osive]

Can we add link in the mdinclude instead of relative path?

[n8henrie]

Thank you -- much cleaner solution than adding another dependency (m2r2)