"""Electrical impedance is the measure of the opposition that a circuit presents to a current when a voltage is applied. Impedance extends the concept of resistance to alternating current (AC) circuits. Source: https://en.wikipedia.org/wiki/Electrical_impedance """ from __future__ import annotations from math import pow, sqrt def electrical_impedance( resistance: float, reactance: float, impedance: float ) -> dict[str, float]: """ Apply Electrical Impedance formula, on any two given electrical values, which can be resistance, reactance, and impedance, and then in a Python dict return name/value pair of the zero value. >>> electrical_impedance(3,4,0) {'impedance': 5.0} >>> electrical_impedance(0,4,5) {'resistance': 3.0} >>> electrical_impedance(3,0,5) {'reactance': 4.0} >>> electrical_impedance(3,4,5) Traceback (most recent call last): ... ValueError: One and only one argument must be 0 """ if (resistance, reactance, impedance).count(0) != 1: raise ValueError("One and only one argument must be 0") if resistance == 0: return {"resistance": sqrt(pow(impedance, 2) - pow(reactance, 2))} elif reactance == 0: return {"reactance": sqrt(pow(impedance, 2) - pow(resistance, 2))} elif impedance == 0: return {"impedance": sqrt(pow(resistance, 2) + pow(reactance, 2))} else: raise ValueError("Exactly one argument must be 0") if __name__ == "__main__": import doctest doctest.testmod()