zacklib 0.0.1

A small example package

Overview

The goal of this activity is to introduce you to Python’s packaging system, known as PyPI (Python Package Index). PyPI serves as a central repository for contributed Python packages and libraries. It is accessed by the pip tool whenever you install a new package.

Instructions

Part 1

Start by creating a folder for your package inside the src directory. Since package names must be unique, name your folder using the format <your_name>lib, replacing <your_name> with your actual name. Be sure to avoid spaces or special characters in the name.

src/<your_name>lib

Next, create the following file structure for your package.

src
|__<your_name>lib
   |__ __init__.py
   |__ mod.py
|__test.py
|__README.md
|__pyproject.toml

Leave the init.py file empty. This file is required to treat the directory as a Python package, but it doesn’t need to contain any code for basic functionality.

Next, create a file named mod.py inside your package folder. This will be the sole module in your package. Add the following code to it:

def add_one(number):
    return number + 1

Add the following code to test.py. This won’t be a formal test, but rather a simple validation to ensure that your package can be properly imported and used.

from <your_name>lib import mod

print(mod.add_one(5))

Make sure you are able to run test.py from src.

After validating that your package works, add the following configuration to pyproject.toml. Be sure to replace <your_name> with your actual name.

TOML stands for Tom’s Obvious Minimal Language, a simple and readable format used for configuration files. In Python packaging, pyproject.toml defines metadata and build instructions for your package.

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

[project]
name = "<your_name>lib"
version = "0.0.1"
authors = [
  { name="Example Author", email="[e-mail]" },
]
description = "A small example package"
readme = "README.md"
requires-python = ">=3.7"
classifiers = [
    "Programming Language :: Python :: 3",
    "License :: OSI Approved :: MIT License",
    "Operating System :: OS Independent",
]

[project.urls]
"Homepage" = "https://github.com/pypa/sampleproject"
"Bug Tracker" = "https://github.com/pypa/sampleproject/issues"

Write a brief description of your project in README.md. This file cannot be left blank—it should explain what your package does, its purpose, and any basic usage instructions or examples.

Next, try to build your project from the activity’s main folder using the following command:

python3 -m build src

If you encounter an error saying:

No module named 'build'

It means the build module is not installed. You can fix this by running:

pip3 install build

Part 2

Now it’s time to publish your package so others can use it.

• First, create an account at https://pypi.org/.
• Then, go to https://pypi.org/manage/account/ and scroll down to click the “Add API token” button.
• Give your token a name and select “Entire account (all projects)” as the scope.
• Copy the generated token.
• To use the token for publishing, run the following command from the activity’s main folder:

python3 -m twine upload -u __token__ -p <replace with your token> src/dist/*

If you encounter an error saying:

No module named 'twine'

It means the twine module is not installed. You can fix this by running:

pip3 install twine

You can repeat this process multiple times if needed. For example, you may want to update your package. To do that, update the version of your package in pyproject.toml. Next, remove the dist folder and rebuild. Finally, upload the new version.

To test the installation and use of your package from PyPi, create a virtual environment and try to run test.py.

More Information

PyPi user guide is available here.