Concepts: Python Functions

Short essays on why functions in Python work the way they do. These are the pieces you read once and keep coming back to when something surprises you in practice — the "ah, that's why" layer beneath the syntax.

Essays in this section

• Why functions matter — how functions change the shape of the code you write.
• First-class functions in Python — what it means that functions are objects, and why it matters.
• Scope, closures, and namespaces — how Python decides which variable you mean.
• The Zen of functions — principles for writing functions that age well.