i am implementing a program to find the shortest path between two cities using digestra algorithm with hep in python and the last step for me is how can i instead of inserting the data of the cities and distance between them manually i want to link the program with a file that have most of the cities as an example is turkey and retrive the shortest path depending on what the user choose but i dont have any idea of how to do that this is a copy of my code if you want to check it