[Unpopular opinion] Don’t use poetry for Python dependencies

Even though Poetry for Python project management has gained popularity in the last years, and even I used it in a few projects, like any tool, it may not be the perfect fit for every project or team. Here I summarised just a few arguments that could be made against using poetry:

  • Learning Curve: For teams or individuals already familiar with other Python packaging and dependency management tools like pip and virtualenv, or even pipenv, adopting poetry can introduce a learning curve. Understanding poetry’s way of managing dependencies, environments, and packages might require time, effort and numerous mistakes.
  • Overhead for Simple Projects: Poetry provides a comprehensive solution that might be overkill for very simple projects. For small scripts or applications with minimal dependencies, the overhead of managing a poetry environment not be justified. Do you have an API with 5-20 dependencies. Don’t use poetry. Doesn’t make any sense.
  • Performance Concerns: Poetry’s dependency resolution process can be slower than some alternatives, particularly for projects with a large number of dependencies. This could impact the speed of continuous integration builds or the responsiveness of development workflows. Personally, I had situation in which adding a new package and rebuilding the lock file was taking me more than 1 hour.
  • Migration Effort for Existing Projects: Migrating an existing project to poetry from another system can require a non-trivial effort. This includes not only technical changes to how dependencies are managed and packaged but also updating any related documentation, developer guides, and CI/CD pipelines. I faced this challenge and it took a long time to migrate all the projects on poetry and to get it right. Also, in the meantime we had to maintain two systems for the same projects.

While poetry may offer some advantages (and the Internet is full of arguments pro-poetry), weighing these potential drawbacks can help determine if it’s the right choice for your situation.