Building an open-source Python application the right way

If you love Python and love open source like I do, you’d probably be open sourcing something new every day/week/month. Sure that there are quite a lot of articles online that tell you the best practices of writing Python code, testing, packaging, distributing etc, I haven’t really found a good article that highlights what are the best practices/conventions to be followed while building a full fledged and open source Python application. So I decided to write one.

While I know that this was a good idea, I also wanted some sort of template code that I could reuse in every project. Hence, I decided to write one. Meet bootstrapy, a bootstrap python application that takes the pain out of setting up a sample application and lets you focus on writing code and tests for them. As a follow up of the application, I’ll try and explain the purpose of various files in as simple manner as possible.

First, let’s take a look at the directory structure of bootstrapy:

bootstrapy-screenshot
Files

  • AUTHORS.rst - This is where you would add yourself as well as the names of other contributors to your project
  • CHANGELOG - Contains the list of changes in your application for each release you do. This serves as a quick overview of what has changed in your application/project for both developers/users. This file may be optional or mandatory, depending on the license you choose.
  • CONTRIBUTING.rst - Contains the instructions to be followed that instructs developers on how they can help out with your project.
  • MANIFEST.in - While this is not mandatory, it is fairly common to list the contents of your distribution in this file. This file indicates what files are needed to be included in the source distribution but does directly affect what files are installed. In short words, the packages that need to be installed, should be mentioned in setup.py  and the extras needed in the final binary of your application, should be mentioned in the MANIFEST file.
  • Makefile - Makefiles are generally used to organise code compilation. But we can abuse it a bit and use it to do various other things like setting up an environment, installing dependencies, cleaning up……you get the picture.
  • requirements.txt - This is where you put all the dependencies/packages needed by your project/application. Doing so, you can install them using make deps  which internally runs pip install -r requirements.txt
  • setup.py - Tells you that the package/module that you’re about to install have been packaged and distributed using Distutils, which is the standard for distributing Python modules. This allows for easy installation of Python projects by just running  python setup.py install

You can do other things like create your own package, zip it and even upload it to PyPi. For more details, refer Installing Python Modules and Getting started with setuptools and setup.py.

Directories

  • docs - This is the directory to be created to store all the documentation to be used by Sphinx. You should basically store the documentation files in .rst(reStructured Text) format.
  • mypackage - This is the main package of your project. This is where your project/application code goes into. You can see some sample, useless code in myapp.py .
  • tests - This is where all your tests go into. Add all your test cases/suites in this directory and execute them by callingmake test . I have currently configured the project to run tests using Nose. It automagically detects where all your tests are located and then runs them. It is recommended that you follow the pattern ‘test_\<feature-to-be-tested>.py’ while naming files containing test cases for \<feature-to-be-tested>.

So now whenever I need to work on a Python application, all I need to do is to clone the bootstrapy repo, and voila ! I can start writing code. Sweet, isn’t it ?

This is the project structure that I would recommend, but there may be different opinions about the same. If you have a suggestion, feel free to raise an issue on github. If you have a question/feedback instead, ping me directly via email.

Go Top
comments powered by Disqus