Writing documentation

We place a high importance on consistency and readability of documentation. After all, Django was created in a journalism environment! So we treat our documentation like we treat our code: we aim to improve it as often as possible.

Documentation changes generally come in two forms:

  • General improvements: typo corrections, error fixes and better explanations through clearer writing and more examples.
  • New features: documentation of features that have been added to the framework since the last release.

This section explains how writers can craft their documentation changes in the most useful and least error-prone ways.

Getting started with Sphinx

Django’s documentation uses the Sphinx documentation system, which in turn is based on docutils. The basic idea is that lightly-formatted plain-text documentation is transformed into HTML, PDF, and any other output format.

To actually build the documentation locally, you’ll currently need to install Sphinx – sudo pip install Sphinx should do the trick.

Note

Building the Django documentation requires Sphinx 1.0.2 or newer. Sphinx also requires the Pygments library for syntax highlighting; building the Django documentation requires Pygments 1.1 or newer (a new-enough version should automatically be installed along with Sphinx).

Then, building the HTML is easy; just make html (or make.bat html on Windows) from the docs directory.

To get started contributing, you’ll want to read the reStructuredText Primer. After that, you’ll want to read about the Sphinx-specific markup that’s used to manage metadata, indexing, and cross-references.

Commonly used terms

Here are some style guidelines on commonly used terms throughout the documentation:

  • Django – when referring to the framework, capitalize Django. It is lowercase only in Python code and in the djangoproject.com logo.
  • email – no hyphen.
  • MySQL, PostgreSQL, SQLite
  • Python – when referring to the language, capitalize Python.
  • realize, customize, initialize, etc. – use the American “ize” suffix, not “ise.”
  • subclass – it’s a single word without a hyphen, both as a verb (“subclass that model”) and as a noun (“create a subclass”).
  • Web, World Wide Web, the Web – note Web is always capitalized when referring to the World Wide Web.
  • Web site – use two words, with Web capitalized.

Django-specific terminology

  • model – it’s not capitalized.
  • template – it’s not capitalized.
  • URLconf – use three capitalized letters, with no space before “conf.”
  • view – it’s not capitalized.

Guidelines for reStructuredText files

These guidelines regulate the format of our reST (reStructuredText) documentation:

  • In section titles, capitalize only initial words and proper nouns.

  • Wrap the documentation at 80 characters wide, unless a code example is significantly less readable when split over two lines, or for another good reason.

  • The main thing to keep in mind as you write and edit docs is that the more semantic markup you can add the better. So:

    Add ``django.contrib.auth`` to your ``INSTALLED_APPS``...

    Isn't nearly as helpful as:

    Add :mod:`django.contrib.auth` to your :setting:`INSTALLED_APPS`...

    This is because Sphinx will generate proper links for the latter, which greatly helps readers. There's basically no limit to the amount of useful markup you can add.

  • Use intersphinx to reference Python's and Sphinx' documentation.

Django-specific markup

Besides the Sphinx built-in markup, Django's docs defines some extra description units:

  • Settings:

    .. setting:: INSTALLED_APPS

    To link to a setting, use :setting:`INSTALLED_APPS`.

  • Template tags:

    .. templatetag:: regroup

    To link, use :ttag:`regroup`.

  • Template filters:

    .. templatefilter:: linebreaksbr

    To link, use :tfilter:`linebreaksbr`.

  • Field lookups (i.e. Foo.objects.filter(bar__exact=whatever)):

    .. fieldlookup:: exact

    To link, use :lookup:`exact`.

  • django-admin commands:

    .. django-admin:: syncdb

    To link, use :djadmin:`syncdb`.

  • django-admin command-line options:

    .. django-admin-option:: --traceback

    To link, use :djadminopt:`--traceback`.

Documenting new features

Our policy for new features is:

All documentation of new features should be written in a way that clearly designates the features are only available in the Django development version. Assume documentation readers are using the latest release, not the development version.

Our preferred way for marking new features is by prefacing the features' documentation with: ".. versionadded:: X.Y", followed by an optional one line comment and a mandatory blank line.

General improvements, or other changes to the APIs that should be emphasized should use the ".. versionchanged:: X.Y" directive (with the same format as the versionadded mentioned above.

An example

For a quick example of how it all fits together, consider this hypothetical example:

  • First, the ref/settings.txt document could have an overall layout like this:

    ========
    Settings
    ========
    
    ...
    
    .. _available-settings:
    
    Available settings
    ==================
    
    ...
    
    .. _deprecated-settings:
    
    Deprecated settings
    ===================
    
    ...
    
  • Next, the topics/settings.txt document could contain something like this:

    You can access a :ref:`listing of all available settings
    <available-settings>`. For a list of deprecated settings see
    :ref:`deprecated-settings`.
    
    You can find both in the :doc:`settings reference document
    </ref/settings>`.
    

    We use the Sphinx doc cross reference element when we want to link to another document as a whole and the ref element when we want to link to an arbitrary location in a document.

  • Next, notice how the settings are annotated:

    .. setting:: ADMIN_FOR
    
    ADMIN_FOR
    ---------
    
    Default: ``()`` (Empty tuple)
    
    Used for admin-site settings modules, this should be a tuple of
    settings modules (in the format ``'foo.bar.baz'``) for which this site
    is an admin.
    
    The admin site uses this in its automatically-introspected
    documentation of models, views and template tags.
    

    This marks up the following header as the "canonical" target for the setting ADMIN_FOR This means any time I talk about ADMIN_FOR, I can reference it using :setting:`ADMIN_FOR`.

That's basically how everything fits together.

Improving the documentation

A few small improvements can be made to make the documentation read and look better:

  • Most of the various index.txt documents have very short or even non-existent intro text. Each of those documents needs a good short intro the content below that point.

  • The glossary is very perfunctory. It needs to be filled out.

  • Add more metadata targets. Lots of places look like:

    ``File.close()``
    ~~~~~~~~~~~~~~~~

    ... these should be:

    .. method:: File.close()

    That is, use metadata instead of titles.

  • Add more links -- nearly everything that's an inline code literal right now can probably be turned into a xref.

    See the literals_to_xrefs.py file in _ext -- it's a shell script to help do this work.

    This will probably be a continuing, never-ending project.

  • Add info field lists where appropriate.

  • Whenever possible, use links. So, use :setting:`ADMIN_FOR` instead of ``ADMIN_FOR``.

  • Use directives where appropriate. Some directives (e.g. .. setting::) are prefix-style directives; they go before the unit they're describing. These are known as "crossref" directives. Others (e.g. .. class::) generate their own markup; these should go inside the section they're describing. These are called "description units".

    You can tell which are which by looking at in _ext/djangodocs.py; it registers roles as one of the other.

  • Add .. code-block:: <lang> to literal blocks so that they get highlighted.

  • When referring to classes/functions/modules, etc., you'll want to use the fully-qualified name of the target (:class:`django.contrib.contenttypes.models.ContentType`).

    Since this doesn't look all that awesome in the output -- it shows the entire path to the object -- you can prefix the target with a ~ (that's a tilde) to get just the "last bit" of that path. So :class:`~django.contrib.contenttypes.models.ContentType` will just display a link with the title "ContentType".