def find_point(coords, point_list):
    """
    Coordinates represent either the source or destination [x,y] coordinates of a line.
    Given a list of unique points, map one to the given coordinates.
    """

    for p in point_list:
        if p["coordinates"] == coords:
            return p["idx"]

    print("Couldn't find the point -- {}!\n".format(str(point_list)))