Optional Dependencies Extras
Domain: Package Ecosystem
🎯 Motivation
Not every user needs every feature. Extras let users install optional dependencies with pip install yourpkg[feature], keeping the base install lean while enabling power features on demand.
📋 Concrete Example
In pyproject.toml: [project.optional-dependencies] plot = ["matplotlib"]. Users run pip install timeflex[plot] to get plotting support; those who do not need it install plain timeflex with no extra weight.
🔗 Analogy
A phone’s base model has no headphones. If you want them, you buy the “audio bundle.” Most users skip it; those who want it pay a little more — everyone gets exactly what they need.