Comparison of Sphinx and Doxygen for Project Documentation

1. What is Documentation?

Documentation refers to the written or visual information provided to explain how a system, software, or tool works. It plays a crucial role in helping developers, users, and other stakeholders understand how to operate, maintain, and extend a piece of software or a system. In the context of software development, documentation includes user guides, API references, tutorials, and technical manuals that describe the code, functionality, and system behavior.

2. A Brief History of Documentation

The history of documentation has evolved alongside software development. In the early stages of computing, documentation was often sparse and manually maintained. As programming languages and software complexity grew, the need for systematic and comprehensive documentation became apparent. Tools like Doxygen and Sphinx emerged to assist in auto-generating documentation from source code comments, reducing the effort needed for manual documentation. This automation revolutionized how developers created and maintained accurate, up-to-date documentation.

3. Installing Sphinx

Sphinx is a Python-based tool used to create intelligent and beautiful documentation. It is simple to install and supports various output formats. To install Sphinx, follow these steps:

• Before proceeding, verify that Python is installed on your system. You can check this by running:

  python --version
  

• Open a terminal or command prompt in the destination folder and run the following command to install Sphinx:

  pip install sphinx
  

• Make a folder named docs and enter to that folder using the commands:

  mkdir docs
  cd docs
  

• Run the following command to initialize Sphinx:

  sphinx-quickstart
  

• Go to the previous directory using the command:

  cd ..
  

  To automatically generate documentation for your project's modules, run:

  sphinx-apidoc -o docs .
  

  This command generates .rst files for each module in your project, placing them in the docs directory. The . indicates that the current directory is the source of the Python modules.

• Open Your index.rst File and add the word line modules one line after the line of code :caption: Contents:. Make sure that the modules line is indented correctly (usually with 4 spaces or a tab) to signify that it is part of the toctree.

  .. toctree::
     :maxdepth: 2
     :caption: Contents:
     # blank line
     modules # after inserting the new line
  

• At the very start of the conf.py file, add the following lines to import necessary modules and set up the Python path:

  import os
  import sys
  sys.path.insert(0, os.path.abspath(".."))
  

  Here, import os imports the operating system interface to interact with environment variables, import sys imports the system-specific parameters and functions and sys.path.insert(0, os.path.abspath("..")) adds the parent directory to the Python path.

• Add the following extensions in the conf.py file to use certain facilities of Sphinx:

  extensions = ["sphinx.ext.todo", "sphinx.ext.viewcode", "sphinx.ext.autodoc"]

• For Django applications, add the following lines to configure Django settings:

  import django
  # Set the DJANGO_SETTINGS_MODULE environment variable
  os.environ["DJANGO_SETTINGS_MODULE"] = "django_project_name.settings"  # Adjust to the settings path
  # Initialize Django
  django.setup()
  

  Here, import django imports Django for setting it up, os.environ["DJANGO_SETTINGS_MODULE"] = "django_project_name.settings" sets the environment variable for Django settings module and finally django.setup() initializes Django, allowing the user to access Django models and functionality within the documentation.

• Finally, to build the HTML version of your documentation enter to the docs folder and run:

  ./make.bat html
  

  This command compiles the .rst files into HTML files, which one can view in a web browser.

4. Features of Sphinx

Sphinx comes with a wide range of features that make it an excellent tool for documenting Python projects:

• Automatic API Documentation: Sphinx can generate API documentation directly from your code using autodoc extensions.
• Multiple Output Formats: It supports generating documentation in formats like HTML, PDF, LaTeX, ePub, and more.
• Extensibility: Sphinx has numerous extensions, including support for versioning, search functionality, and even code examples.
• reStructuredText: Sphinx uses reStructuredText (reST), a simple yet powerful markup language for writing documentation.
• Cross-referencing: Sphinx allows for easy cross-referencing between code and documentation elements.
• Beautiful Output: Sphinx produces visually appealing and professional-looking documentation.

5. Why We Are Choosing Sphinx Over Doxygen

While both Sphinx and Doxygen are excellent documentation tools, Sphinx is better suited for our project due to the following reasons: -Python-centric: Sphinx is designed primarily for Python projects, making it more aligned with our development environment.

• Better Customization: Sphinx offers more flexibility and customization options, allowing us to tailor the documentation output to our needs.
• ReStructuredText: Sphinx uses reST, which is easier to learn and write compared to the input formats used by Doxygen.
• Community Support: Sphinx has a large and active community, providing numerous extensions, themes, and plugins.
• Readable Documentation: The output generated by Sphinx tends to be more visually attractive and user-friendly.
• Integration with Python Tools: Sphinx integrates seamlessly with other Python tools, making it easier to document complex codebases.

6. Reference

• Sphinx Documnetations
• Sphinx Installation video