How To Sort A List Of X-y Coordinates

I need to sort a list of [x,y] coordinates that looks like this: list = [[1,2],[0,2],[2,1],[1,1],[2,2],[2,0],[0,1],[1,0],[0,0]] The pattern I'm looking for after sorting is: [x,y]

Solution 1:

use sorted with key:

>>> my_list = [[1,2],[0,2],[2,1],[1,1],[2,2],[2,0],[0,1],[1,0],[0,0]]
>>> sorted(my_list , key=lambda k: [k[1], k[0]])
[[0, 0], [1, 0], [2, 0], [0, 1], [1, 1], [2, 1], [0, 2], [1, 2], [2, 2]]

It will first sort on the y value and if that's equal then it will sort on the x value.

I would also advise to not use list as a variable because it is a built-in data structure.

Solution 2:

Define a virtual index Z = (X+Y) now perform quick sort on Z and based on index Z pick elements (X, Y). Points on circle will lead to same Z (and obviously will stick together in sort results)