Александр

Правильно было бы отделить друг от друга интерфейс взаимодействия с пользователем от калькулятора.

import math


class Distance:
    def __init__(self, lat, long):
        self._lat = math.radians(lat)
        self._long = math.radians(long)

    @property
    def lat(self):
        return self._lat

    @property
    def long(self):
        return self._long

    def __repr__(self):
        return f"latitude - {self._lat} longitude - {self._long}"


class DistanceCalculator:
    K_CONST = 6371.01

    def calculate(self, point_a: Distance, point_b: Distance):
        return self.K_CONST * math.acos(
            math.sin(point_a.lat) * math.sin(point_b.lat) +
            math.cos(point_a.lat) * math.cos(point_b.lat) *
            math.cos(point_a.long - point_b.long)
        )


class GUI:
    ACCEPTED_ACTIONS = {1: "Рассчёт дистанции", 2: "Выход"}
    ACCEPTED_ACTIONS_STR = "\n".join([f"{k}: {v}" for k, v in ACCEPTED_ACTIONS.items()])

    def main(self):
        while True:
            action = input(f'Выберите действие:\n{self.ACCEPTED_ACTIONS_STR}\n')

            try:
                int_act = int(action)
                if int_act not in self.ACCEPTED_ACTIONS:
                    raise ValueError('Недопустимый пункт меню')

                if int_act == 1:
                    a = self.get_distance("A")
                    b = self.get_distance("B")
                    calc = DistanceCalculator()
                    distance = calc.calculate(a, b)
                    print(f'Distance between {a} and {b} is {distance}')
                elif int_act == 2:
                    print('Выход')
                    break

            except (TypeError, ValueError) as E:
                print(E)

    def get_distance(self, point: str):
        latitude = float(input(f'Enter the latitude point {point}: '))
        longitude = float(input(f'Enter the longitude point {point}: '))
        return Distance(latitude, longitude)


if __name__ == "__main__":
    gui = GUI()
    gui.main()