sphinx/doc/tutorial/index.rst

.. _tutorial:

===============
Sphinx tutorial
===============

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 <https://breathe.readthedocs.io/>`_.

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.

Getting started
---------------

Setting up your project and development environment
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In a new directory, create a file called ``README.rst`` with the following
content.

.. code-block:: rest

   Lumache
   =======

   **Lumache** (/luˈmake/) 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:

.. code-block:: console

   $ 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:

.. code-block:: console

   (.venv) $ sphinx-build --version
   sphinx-build 4.0.2

If you see a similar output, you are on the right path!

Creating the documentation layout
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Then from the command line, run the following command:

.. code-block:: console

   (.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 :kbd:`Enter`.
- ``> Project name``: Write "``Lumache``" (without quotes) and press
  :kbd:`Enter`.
- ``> Author name(s)``: Write "``Graziella``" (without quotes) and press
  :kbd:`Enter`.
- ``> Project release []``: Write "``0.1``" (without quotes) and press
  :kbd:`Enter`.
- ``> Project language [en]``: Leave it empty (the default, English) and press
  :kbd:`Enter`.

After the last question, you will see the new ``docs`` directory with the
following content.

.. code-block:: text

   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`` and ``Makefile``
  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:`master 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:

.. code-block:: console

   (.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:

.. image:: /_static/tutorial/lumache-first-light.png

There we go! You created your first HTML documentation using Sphinx.

Making some tweaks to the index
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The ``index.rst`` file that ``sphinx-quickstart`` created has some content
already, and it gets rendered as the front page of our HTML documentation.  It
is written in reStructuredText, a powerful markup language.

Modify the file as follows:

.. code-block:: rest

   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:

.. code-block:: console

   (.venv) $ cd docs
   (.venv) $ make html

After running this command, you will see that ``index.html`` reflects the new
changes!

Where to go from here
---------------------

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>`.