distance.py

# Python 3 program for the
# haversine formula
import math

# Python 3 program for the
# haversine formula
def haversine(lat1, lon1, lat2, lon2):

    # distance between latitudes
    # and longitudes
    dLat = (lat2 - lat1) * math.pi / 180.0
    dLon = (lon2 - lon1) * math.pi / 180.0

    # convert to radians
    lat1 = (lat1) * math.pi / 180.0
    lat2 = (lat2) * math.pi / 180.0

    # apply formulae
    a = (pow(math.sin(dLat / 2), 2) +
         pow(math.sin(dLon / 2), 2) *
             math.cos(lat1) * math.cos(lat2));
    rad = 6371
    c = 2 * math.asin(math.sqrt(a))
    return rad * c

# Driver code
lat1 = 51.5007
lon1 = 74.1246
lat2 = 51.6892
lon2 = 74.0445

print(haversine(lat1, lon1,lat2, lon2), "K.M.")