4 min read
Performance Optimization and Profiling
Prerequisites: Performance basics
A profiler measures exactly where a program spends its time,
instead of guessing. Python's built-in cProfile module does this
without any extra installation:
python3 -m cProfile -s cumulative main.py
This prints every function called, how many times, and how long each took in total — sorted so the slowest parts appear first. Optimize the function that's actually shown to dominate the runtime; don't guess.