Python Copier Project Scaffolding — ELI5

Imagine you build a LEGO house from instructions. A month later, LEGO releases better instructions with a stronger roof design. Wouldn’t it be great if you could update just the roof on the house you already built?

That is what Copier does for code projects. Like Cookiecutter, it creates new projects from a template. But Copier remembers which template version you used. When the template gets better — new security settings, updated dependencies, improved folder layout — you run one command and Copier figures out what changed and offers to update your project.

Without this, developers face a frustrating choice: start fresh from the improved template and lose their work, or keep the old structure and miss out on improvements. Copier gives you a third option — merge the improvements into what you already have.

You answer a few questions when creating the project (“What’s the name? Do you want Docker?”), and Copier fills in all the blanks. Later, if the template adds a GitHub Actions workflow you didn’t have, copier update brings it in without touching your custom code.

One thing to remember: Copier is a project blueprint that keeps sending you upgrades, even after you’ve moved in and started decorating.