Writing Documentation for Flake8

The maintainers of Flake8 believe strongly in benefit of style guides. Hence, for all contributors who wish to work on our documentation, we’ve put together a loose set of guidelines and best practices when adding to our documentation.

View the docs locally before submitting

You can and should generate the docs locally before you submit a pull request with your changes. You can build the docs by running:

tox -e docs

From the directory containing the tox.ini file (which also contains the docs/ directory that this file lives in).


If the docs don’t build locally, they will not build in our continuous integration system. We will generally not merge any pull request that fails continuous integration.

Run the docs linter tests before submitting

You should run the doc8 linter job before you’re ready to commit and fix any errors found.

Capitalize Flake8 in prose

We believe that by capitalizing Flake8 in prose, we can help reduce confusion between the command-line usage of flake8 and the project.

We also have defined a global replacement |Flake8| that should be used and will replace each instance with :program:`Flake8`.

Use the prompt directive for command-line examples

When documenting something on the command-line, use the .. prompt:: directive to make it easier for users to copy and paste into their terminal.


.. prompt:: bash

    flake8 --select E123,W503 dir/
    flake8 --ignore E24,W504 dir

Wrap lines around 79 characters

We use a maximum line-length in our documentation that is similar to the default in Flake8. Please wrap lines at 79 characters (or less).

Use two new-lines before new sections

After the final paragraph of a section and before the next section title, use two new-lines to separate them. This makes reading the plain-text document a little nicer. Sphinx ignores these when rendering so they have no semantic meaning.


Section Header


Next Section Header


Surround document titles with equal symbols

To indicate the title of a document, we place an equal number of = symbols on the lines before and after the title. For example:

 Writing Documentation for Flake8

Note also that we “center” the title by adding a leading space and having extra = symbols at the end of those lines.

Use the option template for new options

All of Flake8’s command-line options are documented in the User Guide. Each option is documented individually using the .. option:: directive provided by Sphinx. At the top of the document, in a reStructuredText comment, is a template that should be copied and pasted into place when documening new options.


The ordering of the options page is the order that options are printed in the output of:

flake8 --help

Please insert your option documentation according to that order.

Use anchors for easy reference linking

Use link anchors to allow for other areas of the documentation to use the :ref: role for intralinking documentation. Example:

.. _use-anchors:

Use anchors for easy reference linking
Somewhere in this paragraph we will :ref:`reference anchors


You do not need to provide custom text for the :ref: if the title of the section has a title that is sufficient.

Keep your audience in mind

Flake8’s documentation has three distinct (but not separate) audiences:

  1. Users
  2. Plugin Developers
  3. Flake8 Developers and Contributors

At the moment, you’re one of the third group (because you’re contributing or thinking of contributing).

Consider that most Users aren’t very interested in the internal working of Flake8. When writing for Users, focus on how to do something or the behaviour of a certain piece of configuration or invocation.

Plugin developers will only care about the internals of Flake8 as much as they will have to interact with that. Keep discussions of internal to the mininmum required.

Finally, Flake8 Developers and Contributors need to know how everything fits together. We don’t need detail about every line of code, but cogent explanations and design specifications will help future developers understand the Hows and Whys of Flake8’s internal design.