Decorators

Concepts covered: pyDecorators

Decorators let you extend function behavior without modifying the original code. They are a powerful tool for cross-cutting concerns like logging and timing. The Wrapper Pattern A decorator is a function that takes another function and returns an enhanced version. The wrapper function adds behavior before or after calling the original. Using the @ Syntax Decorators can be stacked by applying multiple @ lines above a function. They are applied from bottom to top, so the decorator closest to the function runs first. Real-world frameworks like Flask and Django use decorators extensively to register routes, enforce authentication, and cache expensive results.

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This section is part of the Python Foundations: Advanced lesson on DataDriven, a free data engineering interview prep platform. Each section includes explanations, worked examples, and hands-on code challenges that execute in real time. SQL queries run against a live PostgreSQL database. Python runs in a sandboxed Docker container. Data modeling problems validate against interactive schema canvases. All content is framed around what data engineering interviewers actually test at companies like Meta, Google, Amazon, Netflix, Stripe, and Databricks.

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