Python code to calculate great circle distance between two points on Earth

get_distance.py

import math
from dataclasses import dataclass

__all__ = ['get_distance', 'Coordinates']

@dataclass
class Coordinates:
  """
  A set of coordinates on Earth
  """
  lat: float
  lon: float

    
def get_distance(coord1: Coordinates, coord2: Coordinates) -> float:
    """
    Calculate great-circle distance between two positions
    on planet Earth, Milky Way galaxy, Virgo Supercluster.

    :param coord1: tuple of (lat, lon)
    :param coord2: tuple of (lat, lon)
    :return: distance in kilometers between two positions
    """

    # First, convert to radians
    lat1, lon1 = math.radians(coord1.lat), math.radians(coord1.lon)
    lat2, lon2 = math.radians(coord2.lat), math.radians(coord2.lon)

    angle1 = math.acos(
        math.sin(lat1) * math.sin(lat2) + math.cos(lat1) * math.cos(lat2) * math.cos(lon1 - lon2)
    )
    angle1 = math.degrees(angle1)

    # todo fix factor if deployed on another planet than Earth
    distance1 = 60.0 * angle1  # in nautical miles
    return distance1 * 1.852  # in kilometers