flask-praetorian Developer Guide

This developer guide will help you get started on working on flask-praetorian in a development environment so that you can add features and run tests


  • python3
  • poetry


This package relies on Poetry for dependency management and packaging.

Install the package for development

In order to install the package for development and to include all its dependencies, navigate to the root project folder and execute this command:

$ poetry install

The full list of dependencies can be found in pyproject.toml

Running tests

This project uses pytest for its unit testing.

Tests are executed by invoking pytest through poetry from the root of the project:

$ poetry run pytest -ra tests

The -ra option is recommended as it will report skipped tests



Documentation for the flask-praetorian package is available on readthedocs.org. It is configured so that new documentation is generated from the flask-praetorian docs directory automatically whenever a new commit is pushed to the master branch. So, developers need not do anything to build documentation.

Adding further documentation

The majority of the automatically generated developer’s guide is produced from python docstrings

This project uses the sphinx extension sphinx-apidoc to generate help pages from the docstrings at the module, class, and function level.

There are several special keywords that can be added to docstrings that have special significance for sphinx. The most useful of these are the :param: and :return: keywords.

Items can be added to the project-wide todo list and notes that is shown in the /help endpoint

Here is an example method with marked up docstring:

def some_method(param1, param2):
    This is a method that does stuff

    :param: param1: This is the first param
    :param: param2: This is the second param
    :return: A string that says 'yo'
    .. todo:: Make this method more awesomer
    .. note:: This is just a lame example
    return 'yo'

Code Style

This project uses the style constraints described in pep8

Please follow the style guide as stated. Also, please enforce the style guide during code reviews.

Useful tools


reStructuredText documents and sphinx documentation can be previewed as they are edited on your workstation using a tool called sphinx-view. It is indispensable when updating this README.rst document or one of the templates for the autognerated sphinx documentation.


The flake8 tool is very useful for checking for compliant code style. Flake8 is included when flask-praetorian is installed with poetry.

The flake8 tool is invoked by targeting a specific source directory:

$ poetry run flake8 flask_praetorian

Particular directories and source files may also be targeted directly

vim Editor plugin

The vim-flake8 plugin for vim is very useful for identifying style issues inside the vim editor. the vim-flake8 plugin is most easily added by using pathogen.

The following vim binding is useful to execute the flake8 check on write for all python source files:

# autocmd BufWritePost *.py call Flake8()

It is most useful to include that in your .vimrc file

Other notes

  • flask-praetorian uses the pendulum to timestamp its JWT tokens with UTC timestamps