code: def wgs84_distance(lat1, lon1, lat2, lon2):
      
      dLat = math.radians(lat2 - lat1)
      dLon = math.radians(lon2 - lon1)
      a = (math.sin(dLat / 2) * math.sin(dLat / 2) +
           math.cos(math.radians(lat1)) * math.cos(math.radians(lat2)) *
           math.sin(dLon / 2) * math.sin(dLon / 2))
      c = 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
      d = EARTH_RADIUS * c
      return d
docs: Distance (in meters) between two points in WGS84 coord system.