How to sort 2d array by row in python?

Question

I have 2d array, dimension 3x10, and I want to sort by values in 2nd row, from lowest to highest value.

Answer 1

Rather than use lambda x: x[1] you can use operator.itemgetter as the key to the sort or sorted functions. itemgetter(n) creates a function that gets the nth item from a list.

>>> matrix = [ [4,5,6], [1,2,3], [7,0,9]]
>>> from operator import itemgetter
>>> sorted(matrix, key=itemgetter(1))
[[7, 0, 9], [1, 2, 3], [4, 5, 6]]