Here is a secret the textbooks bury: if you can read a Python for loop, you already understand most of the math for data science. That scary Σ symbol in a formula is really just Python’s sum() wearing a disguise. This post covers the handful of ideas you truly need, from algebra and vectors to matrices, mean, median, probability, and distributions, and shows every one as plain Python you can run yourself. “Do not worry about your difficulties in mathematics. ... Read More