Tagged python

Your Decimal Engine Is Still Eating Floats: Determinism Is Decided at the Parser Boundary

Switching a calculation engine to decimal arithmetic fixes nothing if the numbers arrive as floats. A spreadsheet stores numeric cells as IEEE-754 doubles, the usual dataframe library infers a float type on read, and constructing a decimal from a float inherits the float's error exactly. The engine then computes precisely on a value that was already wrong, and nothing in the stack will tell you.