Sorting Multidimesional array(newbie)

[Matimus]

Tartifola wrote:
> Hi,
> how can I sort an array like
>
> array([[5, 2],
>        [1, 3]])
>
> along the first column to obtain
>
> array([[1, 3],
>        [5, 2]])
> i.e. keeping track of the ordered couples?
>
> Thanks,
> A

use a sort key:

>>>from operators import getitem
>>>a = [[5,2],[1,3]]
>>>a
[[5, 2], [1, 3]]
>>>a.sort(key=lambda x:getitem(x,0))
>>>a
[[1, 3], [5, 2]]