Concepts: Packages and packaging

Short essays on the ideas behind Python's packaging machinery — the "ah, that's why" layer beneath the syntax. Read once, then come back when something about an import or a release surprises you.

Essays in this section

• How Python's import system works — finders, loaders, the import cache, and the order Python searches.
• Why wheels exist — what an sdist is, what a wheel is, and the compilation problem they were invented to solve.
• The PyPI ecosystem and trust — what PyPI is, the trust model that comes with an open package index, and what to actually do about it.