Make it pretty.

Understanding Python decorators and their practical role

This foundational Python language question tests whether you understand decorators—a core abstraction for wrapping and modifying function or class behaviour without changing their source code. It is a frequent screening question in technical interviews, particularly at firms that rely on Python for research, backtesting, or infrastructure.

The question probes both conceptual grasp and practical awareness: what decorators enable, how they are applied, and why they matter in real codebases. A solid answer connects the mechanism (higher-order functions, function composition) to the motivation (code reuse, separation of concerns, readable syntax). Interviewers often follow up by asking you to write a simple decorator or reason about decorator stacking.

• Function composition and higher-order functions
• Wrapping and delegation patterns
• The @ syntax and how it desugars
• Common use cases: logging, timing, caching, access control