In this tutorial you will build a simple documentation project using Sphinx, and view it in your browser as HTML. The project will include narrative, handwritten documentation, as well as autogenerated API documentation.
The tutorial is aimed towards Sphinx newcomers willing to learn the fundamentals of how projects are created and structured. You will create a fictional software library to generate random food recipes that will serve as a guide throughout the process, with the objective of properly documenting it.
To showcase Sphinx capabilities for code documentation you will use Python, which also supports automatic documentation generation.
Note
Several other languages are natively supported in Sphinx for manual code documentation, however they require extensions for automatic code documentation, like Breathe.
To follow the instructions you will need access to a Linux-like command line and a basic understanding of how it works, as well as a working Python installation for development, since you will use Python virtual environments to create the project.
In a new directory, create a file called README.rst
with the following
content.
Lumache
=======
**Lumache** (/lu'make/) is a Python library for cooks and food lovers that
creates recipes mixing random ingredients.
It is a good moment to create a Python virtual environment and install the
required tools. For that, open a command line terminal, cd
into the
directory you just created, and run the following commands:
$ python -m venv .venv
$ source .venv/bin/activate
(.venv) $ python -m pip install sphinx
Note
The installation method used above is described in more detail in :ref:`install-pypi`. For the rest of this tutorial, the instructions will assume a Python virtual environment.
If you executed these instructions correctly, you should have the Sphinx command line tools available. You can do a basic verification running this command:
(.venv) $ sphinx-build --version
sphinx-build 4.0.2
If you see a similar output, you are on the right path!
Then from the command line, run the following command:
(.venv) $ sphinx-quickstart docs
This will present to you a series of questions required to create the basic
directory and configuration layout for your project inside the docs
folder.
To proceed, answer each question as follows:
> Separate source and build directories (y/n) [n]
: Write "y
" (without quotes) and press Enter.> Project name
: Write "Lumache
" (without quotes) and press Enter.> Author name(s)
: Write "Graziella
" (without quotes) and press Enter.> Project release []
: Write "0.1
" (without quotes) and press Enter.> Project language [en]
: Leave it empty (the default, English) and press Enter.
After the last question, you will see the new docs
directory with the
following content.
docs
├── build
├── make.bat
├── Makefile
└── source
├── conf.py
├── index.rst
├── _static
└── _templates
The purpose of each of these files is:
build/
- An empty directory (for now) that will hold the rendered documentation.
make.bat
andMakefile
- Convenience scripts to simplify some common Sphinx operations, such as rendering the content.
source/conf.py
- A Python script holding the configuration of the Sphinx project. It contains
the project name and release you specified to
sphinx-quickstart
, as well as some extra configuration keys. source/index.rst
- The :term:`root document` of the project, which serves as welcome page and contains the root of the "table of contents tree" (or toctree).
Thanks to this bootstrapping step, you already have everything needed to render the documentation as HTML for the first time. To do that, run this command:
(.venv) $ sphinx-build -b html docs/source/ docs/build/html
And finally, open docs/build/html/index.html
in your browser. You should see
something like this:
There we go! You created your first HTML documentation using Sphinx.
The index.rst
file that sphinx-quickstart
created has some content
already, and it gets rendered as the front page of your HTML documentation. It
is written in reStructuredText, a powerful markup language.
Modify the file as follows:
Welcome to Lumache's documentation!
===================================
**Lumache** (/lu'make/) is a Python library for cooks and food lovers that
creates recipes mixing random ingredients. It pulls data from the `Open Food
Facts database <https://world.openfoodfacts.org/>`_ and offers a *simple* and
*intuitive* API.
.. note::
This project is under active development.
This showcases several features of the reStructuredText syntax, including:
- a section header using
===
for the underline, - two examples of :ref:`rst-inline-markup`:
**strong emphasis**
(typically bold) and*emphasis*
(typically italics), - an inline external link,
- and a
note
admonition (one of the available :ref:`directives <rst-directives>`)
Now to render it with the new content, you can use the sphinx-build
command
as before, or leverage the convenience script as follows:
(.venv) $ cd docs
(.venv) $ make html
After running this command, you will see that index.html
reflects the new
changes!
Sphinx supports a variety of formats apart from HTML, including PDF, EPUB,
:ref:`and more <builders>`. For example, to build your documentation
in EPUB format, run this command from the docs
directory:
(.venv) $ make epub
After that, you will see the files corresponding to the e-book under
docs/build/epub/
. You can either open Lumache.epub
with an
EPUB-compatible e-book viewer, like Calibre,
or preview index.xhtml
on a web browser.
Note
To quickly display a complete list of possible output formats, plus some
extra useful commands, you can run make help
.
Each output format has some specific configuration options that you can tune,
:ref:`including EPUB <epub-options>`. For instance, the default value of
:confval:`epub_show_urls` is inline
, which means that, by default, URLs are
shown right after the corresponding link, in parentheses. You can change that
behavior by adding the following code at the end of your conf.py
:
# EPUB options
epub_show_urls = 'footnote'
With this configuration value, and after running make epub
again, you will
notice that URLs appear now as footnotes, which avoids cluttering the text.
Sweet!
Note
Generating a PDF using Sphinx can be done running make latexpdf
,
provided that the system has a working \LaTeX installation,
as explained in the documentation of :class:`sphinx.builders.latex.LaTeXBuilder`.
Although this is perfectly feasible, such installations are often big,
and in general LaTeX requires careful configuration in some cases,
so PDF generation is out of scope for this tutorial.
There are two main ways to customize your documentation beyond what is possible with core Sphinx: extensions and themes.
In addition to these configuration values, you can customize Sphinx even more by using :doc:`extensions </usage/extensions/index>`. Sphinx ships several :ref:`builtin ones <builtin-extensions>`, and there are many more :ref:`maintained by the community <third-party-extensions>`.
For example, to enable the :mod:`sphinx.ext.duration` extension,
locate the extensions
list in your conf.py
and add one element as
follows:
# Add any Sphinx extension module names here, as strings. They can be
# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
# ones.
extensions = [
'sphinx.ext.duration',
]
After that, every time you build your documentation, you will see a short durations report at the end of the console output, like this one:
(.venv) $ make html
...
The HTML pages are in build/html.
====================== slowest reading durations =======================
0.042 temp/source/index
Themes, on the other hand, are a way to customize the appearance of your documentation. Sphinx has several :ref:`builtin themes <builtin-themes>`, and there are also third-party ones.
For example, to use the Furo third-party theme
in your HTML documentation, first you will need to install it with pip
in
your Python virtual environment, like this:
(.venv) $ pip install furo
And then, locate the html_theme
variable on your conf.py
and replace
its value as follows:
# The theme to use for HTML and HTML Help pages. See the documentation for
# a list of builtin themes.
#
html_theme = 'furo'
With this change, you will notice that your HTML documentation has now a new appearance:
The file index.rst
created by sphinx-quickstart
is the :term:`root
document`, whose main function is to serve as a welcome page and to contain the
root of the "table of contents tree" (or toctree). Sphinx allows you to
assemble a project from different files, which is helpful when the project
grows.
As an example, create a new file docs/source/usage.rst
(next to
index.rst
) with these contents:
Usage
=====
Installation
------------
To use Lumache, first install it using pip:
.. code-block:: console
(.venv) $ pip install lumache
This new file contains two :ref:`section <rst-sections>` headers, normal
paragraph text, and a :rst:dir:`code-block` directive that renders
a block of content as source code, with appropriate syntax highlighting
(in this case, generic console
text).
The structure of the document is determined by the succession of heading
styles, which means that, by using ---
for the "Installation" section
after ===
for the "Usage" section, you have declared "Installation" to
be a subsection of "Usage".
To complete the process, add a toctree
:ref:`directive <rst-directives>` at
the end of index.rst
including the document you just created, as follows:
Contents
--------
.. toctree::
usage
This step inserts that document in the root of the toctree, so now it belongs to the structure of your project, which so far looks like this:
index
└── usage
If you build the HTML documentation running make html
, you will see
that the toctree
gets rendered as a list of hyperlinks, and this allows you
to navigate to the new page you just created. Neat!
Warning
Documents outside a toctree will result in WARNING: document isn't
included in any toctree
messages during the build process, and will be
unreachable for users.
One powerful feature of Sphinx is the ability to seamlessly add :ref:`cross-references <xref-syntax>` to specific parts of the documentation: a document, a section, a figure, a code object, etc. This tutorial is full of them!
To add a cross-reference, write this sentence right after the
introduction paragraph in index.rst
:
Check out the :doc:`usage` section for further information.
The :rst:role:`doc` role you used automatically references a specific document
in the project, in this case the usage.rst
you created earlier.
Alternatively, you can also add a cross-reference to an arbitrary part of the project. For that, you need to use the :rst:role:`ref` role, and add an explicit label that acts as a target.
For example, to reference the "Installation" subsection, add a label right before the heading, as follows:
Usage
=====
.. _installation:
Installation
------------
...
And make the sentence you added in index.rst
look like this:
Check out the :doc:`usage` section for further information, including how to
:ref:`install <installation>` the project.
Notice a trick here: the install
part specifies how the link will look like
(in this case, using a specific word so the sentence makes sense), whereas the
<installation>
part refers to the actual label you want to add a
cross-reference to. If you do not include an explicit title, hence using
:ref:`installation`
, the section title will be used (in this case,
Installation
). Both the :doc:
and the :ref:
roles will be rendered
as hyperlinks in the HTML documentation.
You are likely depending on some open source libraries for your own project, and there is a chance those dependencies have their documentation written in Sphinx and available online. One of the powerful features of Sphinx is the ability to generate cross-references to other projects available online, using the :doc:`intersphinx </usage/extensions/intersphinx>` extension.
To enable it, first add sphinx.ext.intersphinx
to the list of extensions:
extensions = [
'sphinx.ext.duration',
'sphinx.ext.intersphinx',
]
The way to know whether you can reference an external project is to check
if it has a publicly available objects.inv
, which can be parsed calling
python -m sphinx.ext.intersphinx
. For example, this is the output for
Sphinx itself:
(.venv) $ python -msphinx.ext.intersphinx https://www.sphinx-doc.org/en/master/objects.inv | grep 'std:doc' --after-context 5
std:doc
changes Changelog : changes.html
contents Sphinx documentation contents : contents.html
development/builders Configuring builders : development/builders.html
development/index Extending Sphinx : development/index.html
development/overview Developing extensions overview : development/overview.html
To link your documentation with the Sphinx one, add a
:confval:`intersphinx_mapping` dictionary to your conf.py
as follows:
intersphinx_mapping = {
'sphinx': ('https://www.sphinx-doc.org/en/master/', None),
}
You can now introduce a cross-reference to the contents
section of the
Sphinx documentation as follows, optionally prefixing it by sphinx:
, the
key you used in the intersphinx_mapping
configuration:
.. note::
This documentation is built on Sphinx,
:doc:`find out more in their docs <sphinx:contents>`.
After you build the HTML documentation with make html
, you will see a link
pointing to that specific page of the Sphinx documentation!
This tutorial covered the very first steps to create a documentation project with Sphinx. To continue learning more about Sphinx, check out the :ref:`rest of the documentation <contents>`.