how to design a algorithm to delete the duplicated 2D points in a points list in python : <p>I have a 2D point list like:</p>

<p><strong>points_list = [[2,1],[3,1],[2,1],[2,2],[2,1],[2,2]]</strong></p>

<p>I want to find the duplicated 2D points, and only leave one copy of each duplicated point in the list. Such that to get a result like:</p>

<p><strong>result_list = [[2,1],[3,1],[2,2]]</strong></p>

<p>I know a stupid method to solve the problem, but cannot find a elegant way. Hoping someone could provide some easy ways. Thanks!</p>
