How do you profile and optimize Python code?

Quick Answer Python profiling tools: cProfile (built-in, function-level timing - python -m cProfile script.py). profile module (pure Python, slower). line_profiler (@profile decorator, line-by-line timing). memory_profiler (memory usage per line). py-spy (sampling profiler, low overhead, production-safe). timeit for benchmarking small code snippets. Always profile before optimizing - don't guess bottlenecks.