Overview

Every model in this vault — a discounted cash flow, a Monte Carlo option price, a covariance matrix — is eventually a sequence of typed values passed through operations that a computer executes exactly as written, with no room for the reader's usual "you know what I mean." This topic is the vault's on-ramp into that discipline: what a program actually is, how a computer runs one, and the handful of primitive objects (int, float, bool, str, None) and operators every later note assumes without re-explaining. It is deliberately short — two lessons — because the goal here is orientation, not depth: get comfortable naming values, evaluating expressions, and reading Python's error categories before Stage 2 introduces the first branch or loop.