In typescript it has a Parameters helper that get all types from function arguments: function sum(a: number, b: number) { return a + b } type SumParameters = Parameters<typeof sum>; function subtract(...params: SumParameters) { return params[0] - params[1] } How can I do the same in python so I don't need to redeclare all types again? This question is different from Python's equivalent of Typescript's Parameters utility type? once it's asking for ConstructorParameters Continue reading...