Multi dimension array slicing in Python

Python has nice properties of slicing lists. See https://stackoverflow.com/questions/509211/pythons-slice-notation

But it won’t work on list of list. For example:

l = [[1,2,3],[4,5,6],[7,8,9]] and we would like to grab 1st and 3rd columns of l with following:

l[:][0,2]

it won’t work (TypeError: list indices must be integers, not tuple)

For some reason Python doesnt really support slicing on multi-dimensional list. You have to convert it to Numpy array to do so:

np.array(l)[:,[0,2]]

nice and easy. More see http://ilan.schnell-web.net/prog/slicing/