main.py

from typing import Dict, List


def main():
    bus_admittances: Dict[str, complex] = {
        "1-2": 2.5 - 4j,
        "1-3": 1 - 2j,
        "2-3": 1.5 - 2j,
        "1-0": 0.4 - 1j,
        "2-0": 0.5 - 1j,
    }

    busses: List[str] = []

    for bus in bus_admittances.keys():
        bus_split: List[str] = bus.split("-")
        for bus_split_item in bus_split:
            if bus_split_item not in busses and bus_split_item != "0":
                busses.append(bus_split_item)

    admittance_matrix: List[List[complex]] = [
        [0 for _ in range(len(busses))] for _ in range(len(busses))]
    print(admittance_matrix)

    for bus, admittance in bus_admittances.items():
        bus_split: List[str] = bus.split("-")

        x: int = int(bus_split[0])
        y: int = int(bus_split[1])

        if x != 0 and y != 0:
            x -= 1
            y -= 1

            admittance_matrix[x][y] = -admittance
            admittance_matrix[y][x] = -admittance

            admittance_matrix[x][x] += admittance
            admittance_matrix[y][y] += admittance

        elif x == 0 and y != 0:
            y -= 1
            admittance_matrix[y][y] += admittance

        elif x != 0 and y == 0:
            x -= 1
            admittance_matrix[x][x] += admittance

        print(admittance_matrix)


if __name__ == '__main__':
    main()