code: def face_distance(face_encodings, face_to_compare):
      
      if len(face_encodings) == 0:
          return np.empty((0))
  
      return np.linalg.norm(face_encodings - face_to_compare, axis=1)
docs: Given a list of face encodings, compare them to a known face encoding and get a euclidean distance
      for each comparison face. The distance tells you how similar the faces are.
  
      :param faces: List of face encodings to compare
      :param face_to_compare: A face encoding to compare against
      :return: A numpy ndarray with the distance for each face in the same order as the 'faces' array