Recipes: Python Functions

Short, task-focused how-tos for specific things you'll want to do with functions. Each recipe assumes you already know the basics — if a term surprises you, the Learn section is one click away.

Unlike the tutorials, the recipes don't have a recommended order. Pick whichever is useful right now.

Recipes in this guide

• Use default and keyword arguments effectively — practical patterns for flexible function signatures.
• Write recursive functions — the shape of a good recursive function and the pitfalls to avoid.
• Create decorators — writing your own decorators that wrap other functions.
• Work with higher-order functions — map, filter, function composition, and when to reach for each.
• Validate function arguments — catching bad inputs early and giving clear errors.