'Returns the euclidean distance if the input is of the form [(x1, y1), (x2, y2)]'

def __distance(self, li):

    return math.sqrt(math.fsum((math.pow(math.fsum((int(li[1][0]), (- int(li[0][0])))), 2), math.pow(math.fsum((int(li[1][1]), (- int(li[0][1])))), 2))))
