distance_calculation.py

# credit - zsoobhan from SO (https://stackoverflow.com/questions/46731426/show-distance-in-km-or-m-of-each-restaurant/46732398#46732398) 

def calculate_distance(restaurant, current_lat, current_long):
    from django.contrib.gis.geos import GEOSGeometry
    pnt = GEOSGeometry(restaurant.location)
    pnt2 = GEOSGeometry('SRID=4326;POINT({0} {1})'.format(
        current_long, current_lat))
    print(pnt.distance(pnt2) * 100)
    return round(pnt.distance(pnt2) * 100, 2)


def nearby_restaurant_finder(request, current_lat, current_long):
    from django.contrib.gis.geos import Point
    from django.contrib.gis.measure import D
    user_location = Point(float(current_long), float(current_lat))
    distance_from_point = {'km': 500}
    restaurants = Restaurant.gis.filter(
        location__distance_lte=(user_location, D(**distance_from_point)))
    restaurants = restaurants.distance(user_location).order_by('distance')
    ctx_restaurants = [
        {
            'name': restaurant.name,
            'distance_from_user': calculate_distance(restaurant, current_lat, current_long)
        }
        for restaurant in restaurants
    ]

    context = {
        'restaurants': ctx_restaurants
    }
    return render(request, 'restaurant/nearby_restaurant.html', context)