How to Create and Publish Your Own Python Package

Before we start, ensure you have:

• Basic knowledge of Python programming.
• Python 3.6 or higher installed.
• pip installed.

A well-organized project structure is crucial, as the intention here is that this is a package that will out live individual projects and be maintained for many years, potentially by multiple teams. You need to ensure you have tests, and clear documentation. Here’s a basic template:

Obviously your package isn’t going to be much use if it doesn’t do anything. I’ve created two basic modules. The first can do addition and subtraction, while the second can do multiplication and division.

The __init__.py file makes Python treat the directory as a package. Create package_publishing/__init__.py:

# package_publishing/__init__.py

from .module1 import add, subtract
from .module2 import multiply, divide

Testing ensures your package works as expected. Create tests/test_module1.py:

# tests/test_module1.py

import unittest
from package_publishing import add, subtract

class TestModule1(unittest.TestCase):

    def test_add(self):
        self.assertEqual(add(1, 2), 3)
        self.assertEqual(add(-1, 1), 0)
    
    def test_subtract(self):
        self.assertEqual(subtract(2, 1), 1)
        self.assertEqual(subtract(2, 3), -1)

if __name__ == "__main__":
    unittest.main()
    

Note: setup.py is obsolete. Use project.toml instead. https://packaging.python.org/en/latest/tutorials/packaging-projects/

The setup.py file is essential for packaging. Create setup.py:

from setuptools import setup, find_packages

setup(
    name="package_publishing",
    version="0.1",
    packages=find_packages(),
    install_requires=[],
    author="Andy",
    author_email="andy@dont_spam_me.co",
    description="A simple example private package",
    long_description=open("README.md").read(),
    long_description_content_type="text/markdown",
    url="https://github.com/nydasco/package_publishing",
    classifiers=[
        "Programming Language :: Python :: 3",
        "License :: OSI Approved :: MIT License",
        "Operating System :: OS Independent",
    ],
    python_requires='>=3.6',
)