Python's Decimal module stores decimal numbers exactly, not as binary approximations. This matters in treasury work where rounding errors in interest accruals, position valuations, and regulatory calculations can breach thresholds or break audit trails.
Python's integers and floats look similar but behave differently, and mixing them carelessly leads to silent errors in financial calculations. Learn how to handle numbers correctly, when to use Decimal for money, and the pitfalls that catch most practitioners.
